== Methods ==
The Software Freedom Law Center says <ref>https://www.softwarefreedom.org/resources/2014/SFLC-Guide_to_GPL_Compliance_2d_ed.html</ref>><ref>https://www.softwarefreedom.org/resources/2014/SFLC-Guide_to_GPL_Compliance_2d_ed.html</ref>
You can generally do this at the 'file scope' or the 'project scope' (also called "centralized notice").<ref>http://softwarefreedom.org/resources/2012/ManagingCopyrightInformation.html</ref> We believe project scope is the best way to do this, in conjunction with good [[Version Control]] (and also contributor [[assignment]] agreements).
== Enforcement ==
There isn't some big government agency like the FBI (who prosecutes you if you copy a movie) working to ensure that free code remains free. Instead, the effort is literally left to the little guy. The [https://www.softwarefreedom.org/ Software Freedom Law Center] and [https://sfconservancy.org/ Software Freedom Conservancy] is are the main actor actors in enforcement. They are The latter is a charity drawing their financial support from individuals. https://sfconservancy.org/copyleft-compliance/principles.html Meanwhile, the big guys certainly do have lots of money to enforce violations of their licenses (http://www.bsa.org/).
== Resources ==
'''Eben Moglen''' is director of the [https://www.softwarefreedom.org/ Software Freedom Law Center]. See their guide https://www.softwarefreedom.org/resources/2014/SFLC-Guide_to_GPL_Compliance_2d_ed.html Note: Bradley Kuhn and Karen Sandler, who used to work under the umbrella of the [[wp:Software Freedom Law Center]] (SFLC) have since launched their own initiative, the [[wp:Software Freedom Conservancy]].
'''Bradley Kuhn''' (and the FSF?) put together https://copyleft.org where you can find
; https://copyleft.guide : Copyleft and the GNU General Public License: A Comprehensive Tutorial and Guide
; https://gpl.guide : Part I Detailed Analysis of the GNU GPL and Related Licenses