We recommend using a citation manager to remove duplicate articles before importing your references into Covidence. Covidence automatically removes some duplicates, but is by no means perfect. You can check the number of duplicate articles Covidence removed, click on the Import Studies button at the top of your review.
On the Manage Imports tab, you will be able to see how many duplicates were removed and verify their accuracy.
Covidence comes pre-populated with two tags: Ongoing Study, and Awaiting Classification. To use tags, simply check the box to the left-hand side of those citations you wish to tag. You can add a new tag to this list by typing your term in the "Tag with:" field and clicking "create new". Once created and applied to references, you can also filter by these tags. This can be especially useful to get a quick count of how many references received each tag.