Most bibliographic styles stipulate different formats for authored books and edited books. Zotero should provide document types for "book" and "edited book."
@wfon -- in my experience, this isn't true. The only thing that is formatted differently is the contributor (the editor gets a role description added).
the only reason endnote has an edited book item type is because it is not a relational db --it doesn't have a separate author table and therefore needs a special field for editors. zotero should be able to add "ed." after creators' names if author type is "editor"--there is no need for a special item type.
I just want to add to this old thread-- I still think there should be a separate reference type for edited book. As it is, every time I import new books, if they are edited volumes I have to go in and change "contributor" to "editor" (please correct me if I am wrong)-- that is a small labor, but I have to remember to do it. Other comparable programs seem to be able to detect that it is edited without my intervention.
@bess: I suspect the problem you are having is a problem with either the original data (library sourced records often aren't very specific about contributors), or with the conversion code. It's not a consequence of not having an "edited book" type.
Upgrade Storage
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And what's the current behavior? I'll have to check that out...