Okay so gallery 16.0.0 is the most current fully functional gallery app for nc 11 and gallery+ 16 will be the backport of gallery(nonplus) 16 for nc 10?
As gallery+ 15.1.1 is the most current “+” one, I guess it’s the gallery(nonplus) 15 backport for nc 9.x?
As, there it is also clarified in the release topic 
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This was also confusing for me until now. Good to know 