>>>>> On Sat, 23 Jun 2018, Andreas K Huettel wrote:

> As discussed on IRC, regarding the CC license version "3.0 or later for 
> existing projects, 4.0 or later for new projects" sounds like a good plan.

I've updated item b) in the Licensing section:

 a) The GNU General Public License, version 2 or later (GPL-2+)
    [#GPL-2]_.
 
-b) The Creative Commons Attribution-ShareAlike 3.0 License
-   (CC-BY-SA-3.0, only for documentation) [#CC-BY-SA-3.0]_.
-   *[Note: or version 4.0, to be decided]*
+b) The Creative Commons Attribution-ShareAlike 4.0 License
+   (CC-BY-SA-4.0, only for documentation) [#CC-BY-SA-4.0]_.
+   Existing projects may also stay with CC-BY-SA-3.0 [#CC-BY-SA-3.0]_.
 
 c) A license approved as GPL compatible by the Free Software
    Foundation [#GPL-COMPAT]_.