Use this tag for questions where the desired goal is to match a pattern, for the purpose of excluding it from the end result.
Inverse matching is used to select a pattern from within text, and then "match" everything except for the pattern. Situations where this might be prudent often arise when it's easier to match bad content than it is to match the desired content.
Regular expressions are often implicated with this tag; the behavior can be emulated (to an extent) with a tempered greedy token.
In SQL, a FULL OUTER JOIN without intersection will "inverse match" an INNER JOIN, selecting data from the left and right tables if and only if the data does not have a match in the other table.
In set theory, the union of A and B minus the intersection of A and B
(a | b) - (a & b)leaves behind the opposite of the intersection - a set where the data is present in only A or B, not both.
