Flag weight is a measure of how well a user raises flags. Users with a history of flagging helpfully — as judged by moderators who act on those flags — earn high flag weight, and vice versa.
All users start with flag weight of 100. Scores can fall to as low as 0 and rise to as high as 750.
Between Feb. 22, 2011 and Jan. 20, 2012, flag weight was displayed in users' profiles and used to award the Deputy and Marshal badges. Due to sustained community disapproval of flag weight, it was replaced in user profiles by a "number of helpful flags" count, though it continues to be used behind the scenes for ordering flags in each site's moderation queue. The count is a link that leads to the flag summary page.
The tag is used for questions about flag-weight-related decisions, flag weight calculations and how flag weight values are/should be used.