Today I used the German localization of Logos when I looked at the collection entries for a recently built PB and found it was listed as belonging to my recent collections non-PBs and Vyrsobooks!
This is obviously wrong - and is not the case in the English UI:

The bug is in the unfortunate overlocalization of metadata names, such as type and edition, used by collection rules.
The rules are straightforward and as follows: non-PBs are edition:l OR edition:e
in English UI

switching to German UI this same collection now has over 300 more books: the PBs!

Vyrsobooks are edition:e

and again under German UI the collection yields wrong results:
most probably the 'e' from 'erstellt' (German for created) triggers the collection rule.
Thus:
- buggy behavior: collection content changes with different UI, leading to wrong results.
- expected behavior: collection content remains the same regardless of UI
- hints for solution:
- I can imagine that other software build an internal representation of such data (the three types maybe 0, 1, 2) and have the rules translated into this internal code and run against it. Maybe Logos does the same, but trips up on the way.
- Or track the source language of a rule and run it against that language's identifiers.
- Or translate the rules on startup: edition:u for user becomes edition:B - the relevant issue would be not to have different matches, easy to realize here ("benutzererstellt" or "selbsterstellt" as one word is more elegant than the clumsy three words "vom Benutzer erstellt"), much more tricky in the ever-growing list of types.