Citation keys (and other fields) migrated out of the `extra` field, what happens to mixed-client synced groups?

[Emiliano Heyns]

Now that beta8 migrates data from the `extra` field, what happens if Z8 en Z7 both sync to a common group? Is the following scenario possible?

• Z7 adds a `Citation Key:` line to the `extra` field, and syncs
• Z8 pulls in the changes, lifts the keys out of the `extra` field; this will save them, and trigger a sync
• Z7 pulls in the changes, citation key is lost on the Z7 side

or are there safeguards against this scenario in place?

[Dan Stillman]

or are there safeguards against this scenario in place? --

New fields can never be synced to older versions that don't support them. If there's data in an unsupported field, no further updates for that item will sync down. So if a key is moved to the new Citation Key field in Z8, that item will no longer sync to Z6 or Z7.

In a personal library, the user will see a sync warning ("Some data in my library could not be downloaded. It may have been saved with a newer version of Zotero. Other data will continue to sync.")

In a group library, we don't show a warning icon to avoid confusing group users, but I believe we show the same message in the tooltip if you hover over the sync icon.

[Dan Stillman]

On 1/2/26 11:18 AM, Dan Stillman wrote:
> New fields can never be synced to older versions that don't support
> them. If there's data in an unsupported field, no further updates for
> that item will sync down. So if a key is moved to the new Citation Key
> field in Z8, that item will no longer sync to Z6 or Z7.

(But as a reminder, we'll be pushing new versions of Z7 and the mobile
apps soon — probably next week — with the same new fields and migrations.)