Comments let you discuss an item with colleagues without changing its content. A comment can be anchored to a passage of text or attached to the item as a whole, and every comment starts a thread that others can reply to.
Commenting on text
Select any part of an item's text and click Comment in the toolbar that appears.
Type your comment and press Enter to post it (use Shift+Enter for a new line). The selected text stays highlighted; click the highlight later to reopen the thread.
Mentioning colleagues
Type @ in any comment or reply to mention a colleague. Pick a name from the list to add them to the discussion. Mentioned people get a You were mentioned in a comment notification (see Notifications). In the document view, an item shows a speech-bubble icon when you have unresolved discussions or mentions on it; hover it for the count and click it to open the Comments screen.
The Comments screen
Open an item's sidebar and choose the Comments tab to see every thread on the item, each quoting the text it refers to. Use Search comments to find a thread by its text or author. The dropdown next to it switches between All, Open and Resolved threads. Type in the box at the bottom to add a comment on the whole item rather than on a passage.
Replies, edits and resolving
Hover a thread to see its actions. Click the tick to Resolve it once the discussion is settled. Resolved threads disappear from the text and are dimmed in the sidebar, where you can filter for them and reopen one with Unresolve comment. The author of a comment, or anyone who can edit the item, can resolve a thread.
The ... menu offers Copy link, which copies a URL that opens the item with that thread visible, and for your own comments Edit and Delete. Expand a thread to read the replies and write your own; you can edit and delete your own replies too.
Comments in reviews and test runs
Commenting works the same way on items under review and on test cases inside a test run. In a review, comments are attached to the reviewed version of the item, and participants can also reply to each other's feedback. See the Reviews and Test management articles. Comments on baseline items are shown read-only.