Merge remote-tracking branch 'upstream/master'

3 files changed, 146 insertions, 1102 deletions

diff --git a/doc/COPYING.GPLv2 b/doc/COPYING.GPLv2
deleted file mode 100644
index d159169d10..0000000000
--- a/doc/COPYING.GPLv2
+++ /dev/null
@@ -1,339 +0,0 @@
-                    GNU GENERAL PUBLIC LICENSE
-                       Version 2, June 1991
-
- Copyright (C) 1989, 1991 Free Software Foundation, Inc.,
- 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- Everyone is permitted to copy and distribute verbatim copies
- of this license document, but changing it is not allowed.
-
-                            Preamble
-
-  The licenses for most software are designed to take away your
-freedom to share and change it.  By contrast, the GNU General Public
-License is intended to guarantee your freedom to share and change free
-software--to make sure the software is free for all its users.  This
-General Public License applies to most of the Free Software
-Foundation's software and to any other program whose authors commit to
-using it.  (Some other Free Software Foundation software is covered by
-the GNU Lesser General Public License instead.)  You can apply it to
-your programs, too.
-
-  When we speak of free software, we are referring to freedom, not
-price.  Our General Public Licenses are designed to make sure that you
-have the freedom to distribute copies of free software (and charge for
-this service if you wish), that you receive source code or can get it
-if you want it, that you can change the software or use pieces of it
-in new free programs; and that you know you can do these things.
-
-  To protect your rights, we need to make restrictions that forbid
-anyone to deny you these rights or to ask you to surrender the rights.
-These restrictions translate to certain responsibilities for you if you
-distribute copies of the software, or if you modify it.
-
-  For example, if you distribute copies of such a program, whether
-gratis or for a fee, you must give the recipients all the rights that
-you have.  You must make sure that they, too, receive or can get the
-source code.  And you must show them these terms so they know their
-rights.
-
-  We protect your rights with two steps: (1) copyright the software, and
-(2) offer you this license which gives you legal permission to copy,
-distribute and/or modify the software.
-
-  Also, for each author's protection and ours, we want to make certain
-that everyone understands that there is no warranty for this free
-software.  If the software is modified by someone else and passed on, we
-want its recipients to know that what they have is not the original, so
-that any problems introduced by others will not reflect on the original
-authors' reputations.
-
-  Finally, any free program is threatened constantly by software
-patents.  We wish to avoid the danger that redistributors of a free
-program will individually obtain patent licenses, in effect making the
-program proprietary.  To prevent this, we have made it clear that any
-patent must be licensed for everyone's free use or not licensed at all.
-
-  The precise terms and conditions for copying, distribution and
-modification follow.
-
-                    GNU GENERAL PUBLIC LICENSE
-   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
-
-  0. This License applies to any program or other work which contains
-a notice placed by the copyright holder saying it may be distributed
-under the terms of this General Public License.  The "Program", below,
-refers to any such program or work, and a "work based on the Program"
-means either the Program or any derivative work under copyright law:
-that is to say, a work containing the Program or a portion of it,
-either verbatim or with modifications and/or translated into another
-language.  (Hereinafter, translation is included without limitation in
-the term "modification".)  Each licensee is addressed as "you".
-
-Activities other than copying, distribution and modification are not
-covered by this License; they are outside its scope.  The act of
-running the Program is not restricted, and the output from the Program
-is covered only if its contents constitute a work based on the
-Program (independent of having been made by running the Program).
-Whether that is true depends on what the Program does.
-
-  1. You may copy and distribute verbatim copies of the Program's
-source code as you receive it, in any medium, provided that you
-conspicuously and appropriately publish on each copy an appropriate
-copyright notice and disclaimer of warranty; keep intact all the
-notices that refer to this License and to the absence of any warranty;
-and give any other recipients of the Program a copy of this License
-along with the Program.
-
-You may charge a fee for the physical act of transferring a copy, and
-you may at your option offer warranty protection in exchange for a fee.
-
-  2. You may modify your copy or copies of the Program or any portion
-of it, thus forming a work based on the Program, and copy and
-distribute such modifications or work under the terms of Section 1
-above, provided that you also meet all of these conditions:
-
-    a) You must cause the modified files to carry prominent notices
-    stating that you changed the files and the date of any change.
-
-    b) You must cause any work that you distribute or publish, that in
-    whole or in part contains or is derived from the Program or any
-    part thereof, to be licensed as a whole at no charge to all third
-    parties under the terms of this License.
-
-    c) If the modified program normally reads commands interactively
-    when run, you must cause it, when started running for such
-    interactive use in the most ordinary way, to print or display an
-    announcement including an appropriate copyright notice and a
-    notice that there is no warranty (or else, saying that you provide
-    a warranty) and that users may redistribute the program under
-    these conditions, and telling the user how to view a copy of this
-    License.  (Exception: if the Program itself is interactive but
-    does not normally print such an announcement, your work based on
-    the Program is not required to print an announcement.)
-
-These requirements apply to the modified work as a whole.  If
-identifiable sections of that work are not derived from the Program,
-and can be reasonably considered independent and separate works in
-themselves, then this License, and its terms, do not apply to those
-sections when you distribute them as separate works.  But when you
-distribute the same sections as part of a whole which is a work based
-on the Program, the distribution of the whole must be on the terms of
-this License, whose permissions for other licensees extend to the
-entire whole, and thus to each and every part regardless of who wrote it.
-
-Thus, it is not the intent of this section to claim rights or contest
-your rights to work written entirely by you; rather, the intent is to
-exercise the right to control the distribution of derivative or
-collective works based on the Program.
-
-In addition, mere aggregation of another work not based on the Program
-with the Program (or with a work based on the Program) on a volume of
-a storage or distribution medium does not bring the other work under
-the scope of this License.
-
-  3. You may copy and distribute the Program (or a work based on it,
-under Section 2) in object code or executable form under the terms of
-Sections 1 and 2 above provided that you also do one of the following:
-
-    a) Accompany it with the complete corresponding machine-readable
-    source code, which must be distributed under the terms of Sections
-    1 and 2 above on a medium customarily used for software interchange; or,
-
-    b) Accompany it with a written offer, valid for at least three
-    years, to give any third party, for a charge no more than your
-    cost of physically performing source distribution, a complete
-    machine-readable copy of the corresponding source code, to be
-    distributed under the terms of Sections 1 and 2 above on a medium
-    customarily used for software interchange; or,
-
-    c) Accompany it with the information you received as to the offer
-    to distribute corresponding source code.  (This alternative is
-    allowed only for noncommercial distribution and only if you
-    received the program in object code or executable form with such
-    an offer, in accord with Subsection b above.)
-
-The source code for a work means the preferred form of the work for
-making modifications to it.  For an executable work, complete source
-code means all the source code for all modules it contains, plus any
-associated interface definition files, plus the scripts used to
-control compilation and installation of the executable.  However, as a
-special exception, the source code distributed need not include
-anything that is normally distributed (in either source or binary
-form) with the major components (compiler, kernel, and so on) of the
-operating system on which the executable runs, unless that component
-itself accompanies the executable.
-
-If distribution of executable or object code is made by offering
-access to copy from a designated place, then offering equivalent
-access to copy the source code from the same place counts as
-distribution of the source code, even though third parties are not
-compelled to copy the source along with the object code.
-
-  4. You may not copy, modify, sublicense, or distribute the Program
-except as expressly provided under this License.  Any attempt
-otherwise to copy, modify, sublicense or distribute the Program is
-void, and will automatically terminate your rights under this License.
-However, parties who have received copies, or rights, from you under
-this License will not have their licenses terminated so long as such
-parties remain in full compliance.
-
-  5. You are not required to accept this License, since you have not
-signed it.  However, nothing else grants you permission to modify or
-distribute the Program or its derivative works.  These actions are
-prohibited by law if you do not accept this License.  Therefore, by
-modifying or distributing the Program (or any work based on the
-Program), you indicate your acceptance of this License to do so, and
-all its terms and conditions for copying, distributing or modifying
-the Program or works based on it.
-
-  6. Each time you redistribute the Program (or any work based on the
-Program), the recipient automatically receives a license from the
-original licensor to copy, distribute or modify the Program subject to
-these terms and conditions.  You may not impose any further
-restrictions on the recipients' exercise of the rights granted herein.
-You are not responsible for enforcing compliance by third parties to
-this License.
-
-  7. If, as a consequence of a court judgment or allegation of patent
-infringement or for any other reason (not limited to patent issues),
-conditions are imposed on you (whether by court order, agreement or
-otherwise) that contradict the conditions of this License, they do not
-excuse you from the conditions of this License.  If you cannot
-distribute so as to satisfy simultaneously your obligations under this
-License and any other pertinent obligations, then as a consequence you
-may not distribute the Program at all.  For example, if a patent
-license would not permit royalty-free redistribution of the Program by
-all those who receive copies directly or indirectly through you, then
-the only way you could satisfy both it and this License would be to
-refrain entirely from distribution of the Program.
-
-If any portion of this section is held invalid or unenforceable under
-any particular circumstance, the balance of the section is intended to
-apply and the section as a whole is intended to apply in other
-circumstances.
-
-It is not the purpose of this section to induce you to infringe any
-patents or other property right claims or to contest validity of any
-such claims; this section has the sole purpose of protecting the
-integrity of the free software distribution system, which is
-implemented by public license practices.  Many people have made
-generous contributions to the wide range of software distributed
-through that system in reliance on consistent application of that
-system; it is up to the author/donor to decide if he or she is willing
-to distribute software through any other system and a licensee cannot
-impose that choice.
-
-This section is intended to make thoroughly clear what is believed to
-be a consequence of the rest of this License.
-
-  8. If the distribution and/or use of the Program is restricted in
-certain countries either by patents or by copyrighted interfaces, the
-original copyright holder who places the Program under this License
-may add an explicit geographical distribution limitation excluding
-those countries, so that distribution is permitted only in or among
-countries not thus excluded.  In such case, this License incorporates
-the limitation as if written in the body of this License.
-
-  9. The Free Software Foundation may publish revised and/or new versions
-of the General Public License from time to time.  Such new versions will
-be similar in spirit to the present version, but may differ in detail to
-address new problems or concerns.
-
-Each version is given a distinguishing version number.  If the Program
-specifies a version number of this License which applies to it and "any
-later version", you have the option of following the terms and conditions
-either of that version or of any later version published by the Free
-Software Foundation.  If the Program does not specify a version number of
-this License, you may choose any version ever published by the Free Software
-Foundation.
-
-  10. If you wish to incorporate parts of the Program into other free
-programs whose distribution conditions are different, write to the author
-to ask for permission.  For software which is copyrighted by the Free
-Software Foundation, write to the Free Software Foundation; we sometimes
-make exceptions for this.  Our decision will be guided by the two goals
-of preserving the free status of all derivatives of our free software and
-of promoting the sharing and reuse of software generally.
-
-                            NO WARRANTY
-
-  11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
-FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW.  EXCEPT WHEN
-OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
-PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED
-OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
-MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  THE ENTIRE RISK AS
-TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU.  SHOULD THE
-PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING,
-REPAIR OR CORRECTION.
-
-  12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
-WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
-REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,
-INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING
-OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED
-TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY
-YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
-PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
-POSSIBILITY OF SUCH DAMAGES.
-
-                     END OF TERMS AND CONDITIONS
-
-            How to Apply These Terms to Your New Programs
-
-  If you develop a new program, and you want it to be of the greatest
-possible use to the public, the best way to achieve this is to make it
-free software which everyone can redistribute and change under these terms.
-
-  To do so, attach the following notices to the program.  It is safest
-to attach them to the start of each source file to most effectively
-convey the exclusion of warranty; and each file should have at least
-the "copyright" line and a pointer to where the full notice is found.
-
-    <one line to give the program's name and a brief idea of what it does.>
-    Copyright (C) <year>  <name of author>
-
-    This program is free software; you can redistribute it and/or modify
-    it under the terms of the GNU General Public License as published by
-    the Free Software Foundation; either version 2 of the License, or
-    (at your option) any later version.
-
-    This program is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-    GNU General Public License for more details.
-
-    You should have received a copy of the GNU General Public License along
-    with this program; if not, write to the Free Software Foundation, Inc.,
-    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
-
-Also add information on how to contact you by electronic and paper mail.
-
-If the program is interactive, make it output a short notice like this
-when it starts in an interactive mode:
-
-    Gnomovision version 69, Copyright (C) year name of author
-    Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
-    This is free software, and you are welcome to redistribute it
-    under certain conditions; type `show c' for details.
-
-The hypothetical commands `show w' and `show c' should show the appropriate
-parts of the General Public License.  Of course, the commands you use may
-be called something other than `show w' and `show c'; they could even be
-mouse-clicks or menu items--whatever suits your program.
-
-You should also get your employer (if you work as a programmer) or your
-school, if any, to sign a "copyright disclaimer" for the program, if
-necessary.  Here is a sample; alter the names:
-
-  Yoyodyne, Inc., hereby disclaims all copyright interest in the program
-  `Gnomovision' (which makes passes at compilers) written by James Hacker.
-
-  <signature of Ty Coon>, 1 April 1989
-  Ty Coon, President of Vice
-
-This General Public License does not permit incorporating your program into
-proprietary programs.  If your program is a subroutine library, you may
-consider it more useful to permit linking proprietary applications with the
-library.  If this is what you want to do, use the GNU Lesser General
-Public License instead of this License.
diff --git a/doc/COPYING.GPLv3 b/doc/COPYING.GPLv3
deleted file mode 100644
index 94a9ed024d..0000000000
--- a/doc/COPYING.GPLv3
+++ /dev/null
@@ -1,674 +0,0 @@
-                    GNU GENERAL PUBLIC LICENSE
-                       Version 3, 29 June 2007
-
- Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>
- Everyone is permitted to copy and distribute verbatim copies
- of this license document, but changing it is not allowed.
-
-                            Preamble
-
-  The GNU General Public License is a free, copyleft license for
-software and other kinds of works.
-
-  The licenses for most software and other practical works are designed
-to take away your freedom to share and change the works.  By contrast,
-the GNU General Public License is intended to guarantee your freedom to
-share and change all versions of a program--to make sure it remains free
-software for all its users.  We, the Free Software Foundation, use the
-GNU General Public License for most of our software; it applies also to
-any other work released this way by its authors.  You can apply it to
-your programs, too.
-
-  When we speak of free software, we are referring to freedom, not
-price.  Our General Public Licenses are designed to make sure that you
-have the freedom to distribute copies of free software (and charge for
-them if you wish), that you receive source code or can get it if you
-want it, that you can change the software or use pieces of it in new
-free programs, and that you know you can do these things.
-
-  To protect your rights, we need to prevent others from denying you
-these rights or asking you to surrender the rights.  Therefore, you have
-certain responsibilities if you distribute copies of the software, or if
-you modify it: responsibilities to respect the freedom of others.
-
-  For example, if you distribute copies of such a program, whether
-gratis or for a fee, you must pass on to the recipients the same
-freedoms that you received.  You must make sure that they, too, receive
-or can get the source code.  And you must show them these terms so they
-know their rights.
-
-  Developers that use the GNU GPL protect your rights with two steps:
-(1) assert copyright on the software, and (2) offer you this License
-giving you legal permission to copy, distribute and/or modify it.
-
-  For the developers' and authors' protection, the GPL clearly explains
-that there is no warranty for this free software.  For both users' and
-authors' sake, the GPL requires that modified versions be marked as
-changed, so that their problems will not be attributed erroneously to
-authors of previous versions.
-
-  Some devices are designed to deny users access to install or run
-modified versions of the software inside them, although the manufacturer
-can do so.  This is fundamentally incompatible with the aim of
-protecting users' freedom to change the software.  The systematic
-pattern of such abuse occurs in the area of products for individuals to
-use, which is precisely where it is most unacceptable.  Therefore, we
-have designed this version of the GPL to prohibit the practice for those
-products.  If such problems arise substantially in other domains, we
-stand ready to extend this provision to those domains in future versions
-of the GPL, as needed to protect the freedom of users.
-
-  Finally, every program is threatened constantly by software patents.
-States should not allow patents to restrict development and use of
-software on general-purpose computers, but in those that do, we wish to
-avoid the special danger that patents applied to a free program could
-make it effectively proprietary.  To prevent this, the GPL assures that
-patents cannot be used to render the program non-free.
-
-  The precise terms and conditions for copying, distribution and
-modification follow.
-
-                       TERMS AND CONDITIONS
-
-  0. Definitions.
-
-  "This License" refers to version 3 of the GNU General Public License.
-
-  "Copyright" also means copyright-like laws that apply to other kinds of
-works, such as semiconductor masks.
-
-  "The Program" refers to any copyrightable work licensed under this
-License.  Each licensee is addressed as "you".  "Licensees" and
-"recipients" may be individuals or organizations.
-
-  To "modify" a work means to copy from or adapt all or part of the work
-in a fashion requiring copyright permission, other than the making of an
-exact copy.  The resulting work is called a "modified version" of the
-earlier work or a work "based on" the earlier work.
-
-  A "covered work" means either the unmodified Program or a work based
-on the Program.
-
-  To "propagate" a work means to do anything with it that, without
-permission, would make you directly or secondarily liable for
-infringement under applicable copyright law, except executing it on a
-computer or modifying a private copy.  Propagation includes copying,
-distribution (with or without modification), making available to the
-public, and in some countries other activities as well.
-
-  To "convey" a work means any kind of propagation that enables other
-parties to make or receive copies.  Mere interaction with a user through
-a computer network, with no transfer of a copy, is not conveying.
-
-  An interactive user interface displays "Appropriate Legal Notices"
-to the extent that it includes a convenient and prominently visible
-feature that (1) displays an appropriate copyright notice, and (2)
-tells the user that there is no warranty for the work (except to the
-extent that warranties are provided), that licensees may convey the
-work under this License, and how to view a copy of this License.  If
-the interface presents a list of user commands or options, such as a
-menu, a prominent item in the list meets this criterion.
-
-  1. Source Code.
-
-  The "source code" for a work means the preferred form of the work
-for making modifications to it.  "Object code" means any non-source
-form of a work.
-
-  A "Standard Interface" means an interface that either is an official
-standard defined by a recognized standards body, or, in the case of
-interfaces specified for a particular programming language, one that
-is widely used among developers working in that language.
-
-  The "System Libraries" of an executable work include anything, other
-than the work as a whole, that (a) is included in the normal form of
-packaging a Major Component, but which is not part of that Major
-Component, and (b) serves only to enable use of the work with that
-Major Component, or to implement a Standard Interface for which an
-implementation is available to the public in source code form.  A
-"Major Component", in this context, means a major essential component
-(kernel, window system, and so on) of the specific operating system
-(if any) on which the executable work runs, or a compiler used to
-produce the work, or an object code interpreter used to run it.
-
-  The "Corresponding Source" for a work in object code form means all
-the source code needed to generate, install, and (for an executable
-work) run the object code and to modify the work, including scripts to
-control those activities.  However, it does not include the work's
-System Libraries, or general-purpose tools or generally available free
-programs which are used unmodified in performing those activities but
-which are not part of the work.  For example, Corresponding Source
-includes interface definition files associated with source files for
-the work, and the source code for shared libraries and dynamically
-linked subprograms that the work is specifically designed to require,
-such as by intimate data communication or control flow between those
-subprograms and other parts of the work.
-
-  The Corresponding Source need not include anything that users
-can regenerate automatically from other parts of the Corresponding
-Source.
-
-  The Corresponding Source for a work in source code form is that
-same work.
-
-  2. Basic Permissions.
-
-  All rights granted under this License are granted for the term of
-copyright on the Program, and are irrevocable provided the stated
-conditions are met.  This License explicitly affirms your unlimited
-permission to run the unmodified Program.  The output from running a
-covered work is covered by this License only if the output, given its
-content, constitutes a covered work.  This License acknowledges your
-rights of fair use or other equivalent, as provided by copyright law.
-
-  You may make, run and propagate covered works that you do not
-convey, without conditions so long as your license otherwise remains
-in force.  You may convey covered works to others for the sole purpose
-of having them make modifications exclusively for you, or provide you
-with facilities for running those works, provided that you comply with
-the terms of this License in conveying all material for which you do
-not control copyright.  Those thus making or running the covered works
-for you must do so exclusively on your behalf, under your direction
-and control, on terms that prohibit them from making any copies of
-your copyrighted material outside their relationship with you.
-
-  Conveying under any other circumstances is permitted solely under
-the conditions stated below.  Sublicensing is not allowed; section 10
-makes it unnecessary.
-
-  3. Protecting Users' Legal Rights From Anti-Circumvention Law.
-
-  No covered work shall be deemed part of an effective technological
-measure under any applicable law fulfilling obligations under article
-11 of the WIPO copyright treaty adopted on 20 December 1996, or
-similar laws prohibiting or restricting circumvention of such
-measures.
-
-  When you convey a covered work, you waive any legal power to forbid
-circumvention of technological measures to the extent such circumvention
-is effected by exercising rights under this License with respect to
-the covered work, and you disclaim any intention to limit operation or
-modification of the work as a means of enforcing, against the work's
-users, your or third parties' legal rights to forbid circumvention of
-technological measures.
-
-  4. Conveying Verbatim Copies.
-
-  You may convey verbatim copies of the Program's source code as you
-receive it, in any medium, provided that you conspicuously and
-appropriately publish on each copy an appropriate copyright notice;
-keep intact all notices stating that this License and any
-non-permissive terms added in accord with section 7 apply to the code;
-keep intact all notices of the absence of any warranty; and give all
-recipients a copy of this License along with the Program.
-
-  You may charge any price or no price for each copy that you convey,
-and you may offer support or warranty protection for a fee.
-
-  5. Conveying Modified Source Versions.
-
-  You may convey a work based on the Program, or the modifications to
-produce it from the Program, in the form of source code under the
-terms of section 4, provided that you also meet all of these conditions:
-
-    a) The work must carry prominent notices stating that you modified
-    it, and giving a relevant date.
-
-    b) The work must carry prominent notices stating that it is
-    released under this License and any conditions added under section
-    7.  This requirement modifies the requirement in section 4 to
-    "keep intact all notices".
-
-    c) You must license the entire work, as a whole, under this
-    License to anyone who comes into possession of a copy.  This
-    License will therefore apply, along with any applicable section 7
-    additional terms, to the whole of the work, and all its parts,
-    regardless of how they are packaged.  This License gives no
-    permission to license the work in any other way, but it does not
-    invalidate such permission if you have separately received it.
-
-    d) If the work has interactive user interfaces, each must display
-    Appropriate Legal Notices; however, if the Program has interactive
-    interfaces that do not display Appropriate Legal Notices, your
-    work need not make them do so.
-
-  A compilation of a covered work with other separate and independent
-works, which are not by their nature extensions of the covered work,
-and which are not combined with it such as to form a larger program,
-in or on a volume of a storage or distribution medium, is called an
-"aggregate" if the compilation and its resulting copyright are not
-used to limit the access or legal rights of the compilation's users
-beyond what the individual works permit.  Inclusion of a covered work
-in an aggregate does not cause this License to apply to the other
-parts of the aggregate.
-
-  6. Conveying Non-Source Forms.
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diff --git a/doc/keymap.md b/doc/keymap.md
index 6f2a663fc8..3ea138ea8f 100644
--- a/doc/keymap.md
+++ b/doc/keymap.md
@@ -1,15 +1,30 @@
 Keymap framework - how to define your keymap
 ============================================
-***NOTE: This is not final version, may be inconsistent with source code and changed occasionally for a while.***
+***NOTE: This is updated for QMK but this is still work in progress.  This may still be inconsistent with the source code.***
+
+QMK is based on TMK.   Understanding the essential changes made should help you understand variable names etc.
+
+## TMK vs. QMK
+
+| Firmware                  |TMK                    |QMK                      |
+|---------------------------|-----------------------|-------------------------|
+| Maintainer                |hasu                   |Jack Humbert et al.      |
+| Build path customization  | `TMK_DIR = ...`       | `include .../Makefile`  |
+| `keymaps` data            | 3D array of `uint8_t` holding **keycode**      | 3D array of `uint16_t` holding **action code**  |
+| `fn_actions` data         | 1D array of `uint16_t` holding **action code** | 1D array of `uint16_t` holding **action code**  |
+
+Since QMK is based on TMK and uses major portion of TMK code as is, understanding the essential changes made should help you understand the code.
 
 ## 0. Keymap and layers
-**Keymap** is comprised of multiple layers of key layout, you can define **32 layers** at most.
-**Layer** is an array of **keycodes** to define **actions** for each physical keys.
-respective layers can be validated simultaneously. Layers are indexed with 0 to 31 and higher layer has precedence.
+In QMK,  **`const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS]`** holds multiple **layers** of keymap information in **16 bit** data holding the **action code**. You can define **32 layers** at most.
 
-    Keymap: 32 Layers                   Layer: Keycode matrix
+For trivial key definitions, the higher 8 bits of the **action code** are all 0 and the lower 8 bits holds the USB HID usage code generated by the key as **keycode**.
+
+Respective layers can be validated simultaneously. Layers are indexed with 0 to 31 and higher layer has precedence.
+
+    Keymap: 32 Layers                   Layer: action code matrix
     -----------------                   ---------------------
-    stack of layers                     array_of_keycode[row][column]
+    stack of layers                     array_of_action_code[row][column]
            ____________ precedence               _______________________
           /           / | high                  / ESC / F1  / F2  / F3   ....
       31 /___________// |                      /-----/-----/-----/-----
@@ -22,11 +37,15 @@ respective layers can be validated simultaneously. Layers are indexed with 0 to
        0 /___________/  V low           0 `--------------------------
 
 
+Sometimes, the action code stored in keymap may be referred as keycode in some documents due to the TMK history.
+
+### 0.1 Keymap layer status
+Keymap layer has its state in two 32 bit parameters:
 
-### 0.1 Keymap status
-Keymap has its state in two parameters:
-**`default_layer`** indicates a base keymap layer(0-31) which is always valid and to be referred, **`keymap_stat`** is 16bit variable which has current on/off status of layers on its each bit.
+* **`default_layer_state`** indicates a base keymap layer(0-31) which is always valid and to be referred.
+* **`layer_state`** () has current on/off status of the layer on its each bit.
 
+Keymap has its state in two parameter **`default_layer`** indicates a base keymap layer(0-31) which is always valid and to be referred, **`keymap_stat`** is 16bit variable which has current on/off status of layers on its each bit.
 Keymap layer '0' is usually `default_layer` and which is the only valid layer and other layers is initially off after boot up firmware, though, you can configured them in `config.h`.
 To change `default_layer` will be useful when you switch key layout completely, say you want Colmak instead of Qwerty.
 
@@ -67,97 +86,132 @@ On the other hand, you shall change `layer_state` to overlay base layer with som
 ### 0.2 Layer Precedence and Transparency
 Note that ***higher layer has higher priority on stack of layers***, namely firmware falls down from top layer to bottom to look up keycode. Once it spots keycode other than **`KC_TRNS`**(transparent) on a layer it stops searching and lower layers aren't referred.
 
-You can place `KC_TRNS` on overlay layer changes just part of layout to fall back on lower or base layer.
-Key with `KC_TRANS` doesn't has its own keycode and refers to lower valid layers for keycode, instead.
+You can place `KC_TRANS` on overlay layer changes just part of layout to fall back on lower or base layer.
+Key with `KC_TRANS` (`KC_TRNS` and `_______` are the alias) doesn't has its own keycode and refers to lower valid layers for keycode, instead.
 See example below.
 
 
 ### 0.3 Keymap Example
-Keymap is **`keymaps[]`** C array in fact and you can define layers in it with **`KEYMAP()`** C macro and keycodes. To use complex actions you need to define `Fn` keycode in **`fn_actions[]`** array.
+Keymap in this QMK is **`static const uint16_t PROGMEM keymaps[]`** C array in fact and you can define layers in it with **`KEYMAP()`** C macro and keycodes. To use complex actions you need to define `Fn` keycode in **`fn_actions[]`** array.  It holds the 16 bit quantum keycode (action code).
+
+> Please note that keymap in the TMK, which QMK was forked from, is **`static const uint8_t PROGMEM keymaps[]`** C array which holds the 8 bit keycode (~USB HID usage code).
 
 This is a keymap example for [HHKB](http://en.wikipedia.org/wiki/Happy_Hacking_Keyboard) keyboard.
-This example has three layers, 'Qwerty' as base layer, 'Cursor' and  'Mousekey'.
+This example has three layers, 'QWERTY' as base layer, 'FN' and  'MOUSE'.
+
 In this example,
 
- `Fn0` is a **momentary layer switching** key, you can use keys on Cursor layer while holding the key.
+ `MO(layer)` is a **momentary layer switching** key.
 
- `Fn1` is a momentary layer switching key with tapping feature, you can get semicolon **';'** with taping the key and switch layers while holding the key. The word **'tap'** or **'tapping'** mean to press and release a key quickly.
+You can find other keymap definitions in file `keymap.c` located on project directories.
+```
+/*
+ * dbroqua HHKB Layout
+ */
+#include "hhkb.h"
+
+#define BASE 0
+#define FN 1
+#define MOUSE 2
+
+const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
+    /* BASE Level: Default Layer
+     * ,-----------------------------------------------------------------------------------------.
+     * | Esc |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  8  |  9  |  0  |  -  |  =  |  \  |  `  |
+     * |-----------------------------------------------------------------------------------------+
+     * | Tab    |  Q  |  W  |  E  |  R  |  T  |  Y  |  U  |  I  |  O  |  P  |  [  |  ]  |  Bksp  |
+     * |-----------------------------------------------------------------------------------------+
+     * | Ctrl    |  A  |  S  |  D  |  F  |  G  |  H  |  J  |  K  |  L  |  ;  |  '  |    Enter    |
+     * |-----------------------------------------------------------------------------------------+
+     * | Shift     |  Z  |  X  |  C  |  V  |  B  |  N  |  M  |  ,  |  .  |  /  | Shift     | fn  |
+     * +-----------------------------------------------------------------------------------------+
+     *         | Gui |  Alt   |               Space               | AltGr |Mouse|
+     *         `----------------------------------------------------------------´
+     */
+    [BASE] = KEYMAP(
+        KC_ESC,   KC_1,  KC_2,  KC_3,  KC_4,  KC_5,  KC_6,  KC_7,  KC_8,     KC_9,    KC_0,     KC_MINS,  KC_EQL,    KC_BSLS,  KC_GRV, \
+        KC_TAB,   KC_Q,  KC_W,  KC_E,  KC_R,  KC_T,  KC_Y,  KC_U,  KC_I,     KC_O,    KC_P,     KC_LBRC,  KC_RBRC,   KC_BSPC,          \
+        KC_LCTL,  KC_A,  KC_S,  KC_D,  KC_F,  KC_G,  KC_H,  KC_J,  KC_K,     KC_L,    KC_SCLN,  KC_QUOT,  KC_ENT,                      \
+        KC_LSFT,  KC_Z,  KC_X,  KC_C,  KC_V,  KC_B,  KC_N,  KC_M,  KC_COMM,  KC_DOT,  KC_SLSH,  KC_RSFT,  MO(FN),                    \
+                        KC_LGUI, KC_LALT,  /*        */ KC_SPC, KC_RALT, MO(MOUSE)
+    ),
+
+    /* FN Layer
+     * ,-----------------------------------------------------------------------------------------.
+     * | Pwr |  F1  | F2  | F3  | F4  | F5  | F6  | F7  | F8  | F9  | F0  | F11 | F12 | Ins | Del|
+     * |-----------------------------------------------------------------------------------------+
+     * | Caps   |     |     |     |     |     |     |     |PrtSc| Slck| Paus|  Up |     |        |
+     * |-----------------------------------------------------------------------------------------+
+     * |         | Vol-| Vol+| Mute|     |     | *   | /   | Home| PgUp| Left |Right|            |
+     * |-----------------------------------------------------------------------------------------+
+     * |           | Prev| Play| Next|     |     | +   | -   | End |PgDwn| Down|           |     |
+     * +-----------------------------------------------------------------------------------------+
+     *         |     |        |                                   | Stop  |     |
+     *         `----------------------------------------------------------------´
+     */
+    [FN] = KEYMAP(
+        KC_PWR,   KC_F1,    KC_F2,    KC_F3,    KC_F4,    KC_F5,    KC_F6,    KC_F7,    KC_F8,    KC_F9,    KC_F10,   KC_F11,   KC_F12,   KC_INS,   KC_DEL, \
+        KC_CAPS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_PSCR,  KC_SLCK,  KC_PAUS,  KC_UP,    KC_TRNS,  KC_TRNS,          \
+        KC_TRNS,  KC_VOLD,  KC_VOLU,  KC_MUTE,  KC_TRNS,  KC_TRNS,  KC_PAST,  KC_PSLS,  KC_HOME,  KC_PGUP,  KC_LEFT,  KC_RGHT,  KC_TRNS,                    \
+        KC_TRNS,  KC_MPRV,  KC_MPLY,  KC_MNXT,  KC_TRNS,  KC_TRNS,  KC_PPLS,  KC_PMNS,  KC_END,   KC_PGDN,  KC_DOWN,  KC_TRNS,  KC_TRNS,                    \
+                        KC_TRNS, KC_TRNS,           KC_TRNS,                KC_MSTP, KC_TRNS
+    ),
+
+    /* MOUSE Layer
+     * ,-----------------------------------------------------------------------------------------.
+     * |     |      |     |     |     |     |     |     |     |     |     |     |     |     |    |
+     * |-----------------------------------------------------------------------------------------+
+     * |        |     | WUp |     |     |     |     |     |     |     | Btn1|  Up | Btn2|        |
+     * |-----------------------------------------------------------------------------------------+
+     * |         | WLt | WDn | WRt |     |     |     |     |     |     | Left |Right|            |
+     * |-----------------------------------------------------------------------------------------+
+     * |           |     |     |     |     |     |     |     |     | Btn3| Down|           |     |
+     * +-----------------------------------------------------------------------------------------+
+     *         |     |        |                                   |       |     |
+     *         `----------------------------------------------------------------´
+     */
+    [MOUSE] = KEYMAP(
+        KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,   KC_TRNS, \
+        KC_TRNS,  KC_TRNS,  KC_WH_U,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_BTN1,  KC_MS_U,  KC_BTN2,  KC_TRNS,          \
+        KC_TRNS,  KC_WH_L,  KC_WH_D,  KC_WH_R,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_MS_L,  KC_MS_R,  KC_TRNS,                    \
+        KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_BTN3,  KC_MS_D,  KC_TRNS,  KC_TRNS,                    \
+                        KC_TRNS, KC_TRNS,           KC_TRNS,                KC_TRNS, KC_TRNS
+    )
+};
 
- `Fn2` is a **toggle layer switch** key, you can stay switched layer after releasing the key unlike momentary switching.
+const uint16_t PROGMEM fn_actions[] = {
 
-You can find other keymap definitions in file `keymap.c` located on project directories.
+};
 
-    static const uint8_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
-        /* 0: Qwerty
-         * ,-----------------------------------------------------------.
-         * |Esc|  1|  2|  3|  4|  5|  6|  7|  8|  9|  0|  -|  =|  \|  `|
-         * |-----------------------------------------------------------|
-         * |Tab  |  Q|  W|  E|  R|  T|  Y|  U|  I|  O|  P|  [|  ]|Backs|
-         * |-----------------------------------------------------------|
-         * |Contro|  A|  S|  D|  F|  G|  H|  J|  K|  L|Fn1|  '|Enter   |
-         * |-----------------------------------------------------------|
-         * |Shift   |  Z|  X|  C|  V|  B|  N|  M|  ,|  .|  /|Shift |Fn0|
-         * `-----------------------------------------------------------'
-         *       |Gui|Alt  |Space                  |Alt  |Fn2|
-         *       `-------------------------------------------'
-         */
-        KEYMAP(ESC, 1,   2,   3,   4,   5,   6,   7,   8,   9,   0,   MINS,EQL, BSLS,GRV, \
-               TAB, Q,   W,   E,   R,   T,   Y,   U,   I,   O,   P,   LBRC,RBRC,BSPC, \
-               LCTL,A,   S,   D,   F,   G,   H,   J,   K,   L,   FN1, QUOT,ENT, \
-               LSFT,Z,   X,   C,   V,   B,   N,   M,   COMM,DOT, SLSH,RSFT,FN0, \
-                    LGUI,LALT,          SPC,                RALT,FN2),
-        /* 1: Cursor(HHKB mode)
-         * ,-----------------------------------------------------------.
-         * |Pwr| F1| F2| F3| F4| F5| F6| F7| F8| F9|F10|F11|F12|Ins|Del|
-         * |-----------------------------------------------------------|
-         * |Caps |   |   |   |   |   |   |   |Psc|Slk|Pus|Up |   |Backs|
-         * |-----------------------------------------------------------|
-         * |Contro|VoD|VoU|Mut|   |   |  *|  /|Hom|PgU|Lef|Rig|Enter   |
-         * |-----------------------------------------------------------|
-         * |Shift   |   |   |   |   |   |  +|  -|End|PgD|Dow|Shift |   |
-         * `-----------------------------------------------------------'
-         *      |Gui |Alt  |Space                  |Alt  |Gui|
-         *      `--------------------------------------------'
-         */ 
-        KEYMAP(PWR, F1,  F2,  F3,  F4,  F5,  F6,  F7,  F8,  F9,  F10, F11, F12, INS, DEL, \
-               CAPS,TRNS,TRNS,TRNS,TRNS,TRNS,TRNS,TRNS,PSCR,SLCK,PAUS,UP,  TRNS,BSPC, \
-               LCTL,VOLD,VOLU,MUTE,TRNS,TRNS,PAST,PSLS,HOME,PGUP,LEFT,RGHT,ENT, \
-               LSFT,TRNS,TRNS,TRNS,TRNS,TRNS,PPLS,PMNS,END, PGDN,DOWN,RSFT,TRNS, \
-                    LGUI,LALT,          SPC,                RALT,RGUI),
-        /* 2: Mousekey
-         * ,-----------------------------------------------------------.
-         * |Esc| F1| F2| F3| F4| F5| F6| F7| F8| F9|F10|F11|F12|Ins|Del|
-         * |-----------------------------------------------------------|
-         * |Tab  |   |   |   |   |   |MwL|MwD|MwU|MwR|   |   |   |Backs|
-         * |-----------------------------------------------------------|
-         * |Contro|   |   |   |   |   |McL|McD|McU|McR|   |   |Return  |
-         * |-----------------------------------------------------------|
-         * |Shift   |   |   |   |   |Mb3|Mb2|Mb1|Mb4|Mb5|   |Shift |   |
-         * `-----------------------------------------------------------'
-         *      |Gui |Alt  |Mb1                    |Alt  |   |
-         *      `--------------------------------------------'
-         * Mc: Mouse Cursor / Mb: Mouse Button / Mw: Mouse Wheel 
-         */
-        KEYMAP(ESC, F1,  F2,  F3,  F4,  F5,  F6,  F7,  F8,  F9,  F10, F11, F12, INS, DEL, \
-               TAB, TRNS,TRNS,TRNS,TRNS,TRNS,WH_L,WH_D,WH_U,WH_R,TRNS,TRNS,TRNS,BSPC, \
-               LCTL,TRNS,ACL0,ACL1,ACL2,TRNS,MS_L,MS_D,MS_U,MS_R,TRNS,QUOT,ENT, \
-               LSFT,TRNS,TRNS,TRNS,TRNS,BTN3,BTN2,BTN1,BTN4,BTN5,SLSH,RSFT,TRNS, \
-                    LGUI,LALT,          BTN1,               RALT,TRNS),
-    };
+const macro_t *action_get_macro(keyrecord_t *record, uint8_t id, uint8_t opt)
+{
+  // MACRODOWN only works in this function
+      switch(id) {
+        case 0:
+          if (record->event.pressed) {
+            register_code(KC_RSFT);
+          } else {
+            unregister_code(KC_RSFT);
+          }
+        break;
+      }
+    return MACRO_NONE;
+};
+```
 
-    static const uint16_t PROGMEM fn_actions[] = {
-        ACTION_LAYER_MOMENTARY(1),                  // FN0
-        ACTION_LAYER_TAP_KEY(2, KC_SCLN),           // FN1
-        ACTION_LAYER_TOGGLE(2),                     // FN2
-    };
 
+## 1. Keycode
+See [`tmk_core/common/keycode.h`](../tmk_core/common/keycode.h) or keycode table below for the detail. Keycode is internal **8bit code** to indicate action performed on key in keymap.  Keycodes are based on [HID Usage Keyboard/Keypad Page(0x07)](http://www.usb.org/developers/hidpage/Hut1_12v2.pdf) plus special codes in the `0xA5-DF` range.
+
+Keycode has `KC_` prefixed symbol respectively. Most of keycodes like `KC_A` have simple action registers key to host on press and unregister on release, while some of other keycodes has some special actions like `Fn` keys, Media control keys, System control keys and Mousekeys.
 
+keymaps[]
 
+In `KEYMAP()` macro, TMK recommends you to keep prefix part `KC_` of keycode to keep keymap compact. For example, just use `A` instead you place `KC_A` in `KEYMAP()`.  But this doesn't apply for QMK. 
 
-## 1. Keycode
-See [`common/keycode.h`](../common/keycode.h) or keycode table below for the detail. Keycode is internal **8bit code** to indicate action performed on key in keymap. Keycode has `KC_` prefixed symbol respectively. Most of keycodes like `KC_A` have simple action registers key to host on press and unregister on release, while some of other keycodes has some special actions like `Fn` keys, Media control keys, System control keys and Mousekeys.
+The `KEYMAP()` macro defines correspondence between the physical key location to the electrical key connection.
 
- ***In `KEYMAP()` macro you should omit prefix part `KC_` of keycode to keep keymap compact.*** For example, just use `A` instead you place `KC_A` in `KEYMAP()`. Some keycodes has 4-letter **short name** in addition to descriptive name, you'll prefer short one in `KEYMAP()`.
+Some keycodes has 7-letter **short name** such as `KC_COMM` in addition to descriptive name `KC_COMMA`, you'll prefer short one in `KEYMAP()`.
 
 ### 1.0 Other key
 - `KC_NO` for no action
@@ -192,7 +246,10 @@ There are 8 modifiers which has discrimination between left and right.
 - `KC_WSCH`, `KC_WHOM`, `KC_WBAK`, `KC_WFWD`, `KC_WSTP`, `KC_WREF`, `KC_WFAV` for web browser operation
 
 ### 1.5 Fn key
-`KC_FNnn` are keycodes for `Fn` key which not given any actions at the beginning unlike most of keycodes has its own inborn action. To use these keycodes in `KEYMAP()` you need to assign action you want at first. Action of `Fn` key is defined in `fn_actions[]` and its index of the array is identical with number part of `KC_FNnn`. Thus `KC_FN0` keycode indicates the action defined in first element of the array. ***32 `Fn` keys can be defined at most.***
+You don't need to use this functionality under QMK since this is a backward compatibility functionality.  Unlike TMK, you can write action code itself directly in  **`static const uint16_t PROGMEM keymaps[]`** C array using `MO(layer)`, etc.
+
+`KC_FNnn` are keycodes for `Fn` key which not given any actions at the beginning unlike most of keycodes has its own inborn action. To use these keycodes in `KEYMAP()` you need to assign action you want at first. Action of `Fn` key is defined in `fn_actions[]` and its index of the array is identical with number part of `KC_FNnn`. Thus `KC_FN0` keycode indicates the action defined in first element of the array. ***Only 32 `Fn` keys can be defined at most.***
+
 
 ### 1.6 Keycode Table
  See keycode table in [`doc/keycode.txt`](./keycode.txt) for description of keycodes.
@@ -549,6 +606,9 @@ Layer switching with tap key:
 
 [dual_role]: http://en.wikipedia.org/wiki/Modifier_key#Dual-role_keys
 
+When user hold a key after tap, it repeat the tapped key rather to hold a modifier key.
+If you prefer to hold a modifier instead, define `TAPPING_FORCE_HOLD` in `config.h`.
+See https://github.com/qmk/qmk_firmware/issues/889 for the detail.
 
 ### 4.2 Tap Toggle
 This is a feature to assign both toggle layer and momentary switch layer action to just same one physical key. It works as momentary layer switch when holding a key but toggle switch with several taps.
@@ -581,15 +641,11 @@ Similar to layer tap toggle, this works as a momentary modifier when holding, bu
 
 
 ## 5. Legacy Keymap
-This was used in prior version and still works due to legacy support code in `common/keymap.c`. Legacy keymap doesn't support many of features that new keymap offers. ***It is not recommended to use Legacy Keymap for new project.***
-
-To enable Legacy Keymap support define this macro in `config.h`.
-
-    #define USE_LEGACY_KEYMAP
+In QMK, `tmk_core/common/keymap.c` is missing and its replacement `quantum/keymap_common.c` lacks Legacy Keymap support.
 
 Legacy Keymap uses two arrays `fn_layer[]` and `fn_keycode[]` to define Fn key. The index of arrays corresponds with postfix number of `Fn` key. Array `fn_layer[]` indicates destination layer to switch and `fn_keycode[]` has keycodes to send when tapping `Fn` key.
 
-In following setting example, `Fn0`, `Fn1` and `Fn2` switch layer to 1, 2 and 2 respectively. `Fn2` registers `Space` key when tapping while `Fn0` and `Fn1` doesn't send any key.
+In the following legacy keymap setting example, `Fn0`, `Fn1` and `Fn2` switch layer to 1, 2 and 2 respectively. `Fn2` registers `Space` key when tapping while `Fn0` and `Fn1` doesn't send any key.
 
     static const uint8_t PROGMEM fn_layer[] = {
         1,              // Fn0
@@ -603,6 +659,7 @@ In following setting example, `Fn0`, `Fn1` and `Fn2` switch layer to 1, 2 and 2
         KC_SPC,         // Fn2
     };
 
+Under QMK, these can be realized using action code ACTION_LAYER_TAP_KEY(1, KC_NO), ACTION_LAYER_TAP_KEY(2, KC_NO), and ACTION_LAYER_TAP_KEY(2, KC_SPC) in the `keymaps` directly.
 
 ## 6. Terminology
 ***TBD***