Comments
Pin a comment to the screen it is about, reply to it, resolve it, and see when it went out of date.
A comment belongs to a screen
A comment is pinned to a publication and to the exact view you were reading: the screen, the viewport and the color scheme. Where the screen can identify the element under your cursor, the comment is pinned to that element as well, so it stays on the right part of the screen when the screen is rendered again.
Threads and replies
The first comment opens a thread and every reply joins it, sharing its anchor. Replies read in order with their author and the time they were written. Comments are plain text of up to 5000 characters; line breaks are kept and only plain HTTP and HTTPS addresses become links.
Open and resolved
A thread is open or resolved. The person who started it and a project admin resolve and reopen it; anyone else with access replies without taking it over. The panel filters by All, Open, Resolved and Outdated, each with its count.
Outdated threads
Outdated is separate from open and resolved. A thread is outdated on a publication whose screen changed or was removed, that no longer has the viewport or color scheme the thread named, or where the element it was pinned to is no longer there. An outdated thread offers View original, and a comment on the current screen starts a new thread.
A screen whose source file moved without changing what it renders has not changed. Where the two views cannot be compared at all, the thread is not treated as unchanged either; it says the comparison is still being worked out.
Writing one
The composer takes the comment and posts it. An empty comment cannot be posted, and a comment that is being saved cannot be posted twice. A write that fails keeps your text and offers Retry, and moving to another screen with a draft asks whether to discard it. A screen with no comments says Start the conversation and offers Add comment.
Who can comment
Reviewers, members and admins of the project comment and reply. You edit and delete your own comments; a project admin can moderate any of them and records why. Approving a publication grants no extra editing rights, and read access to a public project never grants writing.
A thread on a closed or merged pull request is read-only. A thread on a publication that is not linked to a pull request has nothing to sync with and stays editable as long as you have access.