A flag is a kind of status that can be set on bugs or attachments to indicate that the bugs/attachments are in a certain state. Each installation can define its own set of flags that can be set on bugs or attachments.
If your installation has defined a flag, you can set or unset that flag, and if your administrator has enabled requesting of flags, you can submit a request for another user to set the flag.
To set a flag, select either "+" or "-" from the drop-down menu next to the name of the flag in the "Flags" list. The meaning of these values are flag-specific and thus cannot be described in this documentation, but by way of example, setting a flag named "review" to "+" may indicate that the bug/attachment has passed review, while setting it to "-" may indicate that the bug/attachment has failed review.
To unset a flag, click its drop-down menu and select the blank value.
If your administrator has enabled requests for a flag, request a flag by selecting "?" from the drop-down menu and then entering the username of the user you want to set the flag in the text field next to the menu.
A set flag appears in bug reports and on "edit attachment" pages with the abbreviated username of the user who set the flag prepended to the flag name. For example, if Jack sets a "review" flag to "+", it appears as Jack: review [ + ]
A requested flag appears with the user who requested the flag prepended to the flag name and the user who has been requested to set the flag appended to the flag name within parentheses. For example, if Jack asks Jill for review, it appears as Jack: review [ ? ] (Jill).