That is interesting. I consider “Door de jaren heen” to be the title and “Live” to be some sort of subtitle, but the order appears to be consistently reversed on the cover art. I think I´d go for either “Live: Door de jaren heen” or “Live - Door de jaren heen”
For clarity: because the cover and spine are displaying the title differently, I think either option is fine. The guidelines are not clear in this case, I don’t think.
Caveat: I am the dissenting editor in question as well as the editor who originally set the title as-is in MusicBrainz (which is presently “Live – Door de jaren heen”).
I view the guideline as providing a clear means of representing a title and subtitle as linear text when the release itself does not. While the cover does not represent the two as linear text, the spine does. As such, I see the alternative presented (“:”) as unnecessary and follow the spine.
You are correct that there’s room for interpretation here. However, I strongly believe that we should favor the representations given by the release when those representations are suitable for the database.
I am sure you do, but that belief does not compel other editors. If you indeed feel very strongly about this, you could of course propose a modification to the guidelines.
Since I have no dog in this fight, I think I will be taking my leave. I trust that you and Tiske will come to a sensible agreement. If you ever wish to modify the current guidelines, I will be happy to take a look.
In the absence of a clear guideline, I vote in a manner consistent with what I believe leads to the best representation. This does not compel anyone; other editors are free to disagree with me and to vote consistent with their own principles.