Make sure to mention the GNU Project and OSI-provided information regarding...

Make sure to mention the GNU Project and OSI-provided information regarding the GPL so no one tries to disagree with that decision.

doc/development/licensing.md

@@ -12,7 +12,7 @@ Some gems may not include their license information in their `gemspec` file. The
 
 ## Acceptable Licenses
 
-The following are licenses which are acceptable to use:
+Libraries with the following licenses are acceptable for use:
 
 - [The MIT License][MIT] (the MIT Expat License specifically): The MIT License requires that the license itself is included with all copies of the source. It is a permissive (non-copyleft) license as defined by the Open Source Initiative.
 - [LGPL][LGPL] (version 2, version 3): GPL constraints regarding modification and redistribution under the same license are not required of projects using an LGPL library, only upon modification of the LGPL-licensed library itself.
@@ -25,13 +25,15 @@ The following are licenses which are acceptable to use:
 
 ## Unacceptable Licenses
 
-The following are licenses which are *not* acceptable to use:
+Libraries with the following licenses are acceptable for use:
 
 - [GNU GPL][GPL] (version 1, [version 2][GPLv2], [version 3][GPLv3], or any future versions): GPL-licensed libraries cannot be linked to from non-GPL projects.
 - [GNU AGPLv3][AGPLv3]: AGPL-licensed libraries cannot be linked to from non-GPL projects.
 
 ## Notes
 
+Decisions regarding the GNU GPL licenses are based on information provided by [The GNU Project][GNU-GPL-FAQ], as well as [the Open Source Initiative][OSI-GPL], which both state that linking GPL libraries makes the program itself GPL.
+
 If a gem uses a license which is not listed above, open an issue and ask. If a license is not included in the "acceptable" list, operate under the assumption that it is not acceptable.
 
 Keep in mind that each license has its own restrictions (typically defined in their body text). Please make sure to comply with those restrictions at all times whenever an external library is used.
@@ -55,3 +57,5 @@ Gems which are included only in the "development" or "test" groups by Bundler ar
 [GPLv2]: http://www.gnu.org/licenses/gpl-2.0.txt
 [GPLv3]: http://www.gnu.org/licenses/gpl-3.0.txt
 [AGPLv3]: http://choosealicense.com/licenses/agpl-3.0/
+[GNU-GPL-FAQ]: http://www.gnu.org/licenses/gpl-faq.html#IfLibraryIsGPL
+[OSI-GPL]: https://opensource.org/faq#linking-proprietary-code