You're either misremembering or thinking of something in a plugin.
In Zotero itself, you can search for annotation comments and tags and it will match the parent attachment in the items list. Annotations themselves don't currently show in the items list directly, but that's planned.
https://s3.amazonaws.com/zotero.org/images/forums/u6195194/k26c5f7pbz90njeqqc5u.png
In Zotero itself, you can search for annotation comments and tags and it will match the parent attachment in the items list. Annotations themselves don't currently show in the items list directly, but that's planned.