As described under the Organizing Your Library tab, tags can be added by hand or automatically imported with items.
When you click on any tag, the items pane (center column) updates to display only the items with that tag. You can select multiple tags to further refine the results. To remove the filter, click on the tag again or choose Deselect All from the drop-down menu.
Use the search box in this pane to look for tags in the list.
Right-click (Ctrl-click on Macs) on a tag to rename it across all the items or delete it from all the records it is attached to.
The tag selector pane defaults to only showing the tags of items selected in a chosen collection. Choosing Display All Tags in This Library from the drop-down menu will make all your tags visible. You can then apply existing tags to items by selecting the items in the items pane and dragging them onto a tag.
If you have not turned off the Automatically tag items option under Zotero settings and you want to globally remove the tags that have been imported with your items, choose the Delete Automatic Tags in This Library option from the drop-down menu.
Searching collections
Zotero searches citations, notes, and attached PDFs for your search term.
Quick search can be used in three different modes:
Title, Year, Creator - matches against these three fields, as well as publication titles
All Fields & Tags - matches against all fields, as well as tags and text in notes
Everything - matches against all fields, tags, text in notes, and indexed text in PDFs. Zotero automatically indexes PDF and text file attachments when they are added to the Library. In the Advanced section of Zotero sttings, you can refresh the index, clear the index, and choose how much of a document Zotero should index.
You can determine whether an attachment has been indexed by selecting it in the items pane.
The search menu also includes Advanced Search.
Sorting is a quick way to locate items in your library and collections. To sort, click on any of the information categories listed at the top of the item pane. Change the categories displayed by right-clicking on a category and choosing from the drop-down menu.