Editing RetroTechCollection:Copyrights (section)

=== 2.2 Free and Open Licenses ===
Content under a compatible free license may be used, provided attribution and license terms are honored. Accepted licenses include:
* Creative Commons Attribution (CC BY)  
* Creative Commons Attribution-ShareAlike (CC BY-SA)  
* GNU Free Documentation License (GFDL)  
* MIT, BSD, or similarly permissive text licenses  

Include a clear license statement on the page or file description:

<pre>
''Licensed under {{cc-by-sa|4.0}}.'''  
Source: [URL or reference]  
</pre>