Licenses of templates/material for user-created content

Hi,

(cc: calligra-devel only for heads-up, please all discussion on kde-licensing)

I would like some assistance what licenses to propose/use for media (files) 
which are not used as part of the applications, but provided as (raw) material 
for the user-created content. I assume/hope this has been discussed before, 
here or in some other place I can be pointed at.

As result I hope we can update the KDE Licensing policy to also cover that, 
which at least from what I understood is not yet the case.

This is mainly about media files in Calligra, but surely can be generalized. 
There are several apps in Calligra which allow the user to create 
copyrightable content. The content can be of composed nature, like text, 
images and graphics combined in a document. To kickstart that creation, there 
are template files used to create an initial document. Then there are media 
galleries, to allow enriching the documents quickly. And then there is also 
media which is used as mix-in on creating further works, e.g. the UI shell of 
an HTML-based slide show created from a slides document.

These template and media files themselves usually are copyrightable content, 
and could be of composed nature again, thus also different objects with 
different licenses.

The only KDE wiki page I found which had some related content was
https://techbase.kde.org/Policies/Licensing_Policy
where the relevant point might be 
"
11. Standalone media files such as images may be licensed under the Creative 
Commons Attribution-Share Alike 3.0 Unported licence at 
http://creativecommons.org/licenses/by-sa/3.0/ . This does not apply to icons 
or anything which is likely to be mixed with content under our normal (GPL 
etc) licences.
"

What means "may" here exactly?

Should this also include templates, media gallery files and export mix-in 
media? If so, please consider especially the following.

Another open question for me which might influence what we would like to 
recommend/require as licenses (and where the answer ideally could be noted 
somewhere as FAQ):
how does the license of the used template and media files influence the 
license of the created content? There is a term "Derivative work" but I have 
no clue what it means actually & how it can be applied, also not researched it 
yet, hoping that someone here has done that before and can enlight me & else.

Example: someone creates a new presentation from template A, inserts the 
images B & vector graphic C from the media gallery and then exports this as 
HTML slides (like you can do with Stage), where the presentaion shell uses 
image D, CSS file E and HTML/JavaScript code F.

How would licenses game up here?

If e.g. the license of the template influences the document, then requiring CC 
BY-SA 3.0 means every text document written in Words, presentation done in 
Stage or images painted with Krita needs to follow the Attribution and 
ShareAlike requirements, which would be a big blocker surely.


Slightly off-topic, but still related, if the licenses of the templates and 
media files have an influence on the created content, the user should be able 
to see that somehow in the UI, so they know about the legal bounds their 
content gets by using the templates, media files and the mixed-in media on 
export (which might be even more important if hopefully soon also more 
offer/integrate templates and media from online resources, so outside of what 
we control in the KDE repo and releases).
Is that done already in any software, so one could be inspired from how to do 
it?

Cheers
Friedrich