The issue tracker of the zotero-bits repository has been used to collect proposals from the Zotero user community concerning changes to the item types and fields available in Zotero.
The repository was originally created by Avram Lyon (@avram) and available at http://github.com/avram/zotero-bits, but has been migrated in September 2016 to https://github.com/citation-style-language/zotero-bits, as many of the issues are tightly intertwined with CSL.