Two or more translators sometimes edit the same document.
Sometimes they end up translating the same message of the document. This leads to duplication of effort, or lost work, when one saves over changes by the other.
The position of other users in the table is shown with coloured borders. If another user is on the same row of the table, the username is shown as well.
By observing the editing indicators, translators can easily avoid working on a row which another translator is already working on.