These settings can be used to flag result items containing specified expressions in the response. For each item configured in the list, Burp will add a new results column containing a checkbox indicating whether the item was found in each response. You can then sort on this column (by clicking the column header) to group the matched results together.
Using this option can be very powerful in helping to analyze large sets of results, and quickly identifying interesting items. For example, in password guessing attacks, scanning for phrases such as "password incorrect" or "login successful" can locate successful logins; in testing for SQL injection vulnerabilities, scanning for messages containing "ODBC", "error", etc. can identify vulnerable parameters.
In addition to the list of expressions to match, the following options are available:
Match type - This specifies whether the expressions are simple strings or regular expressions.
Case sensitive match - This specifies whether the check for the expression should be case sensitive.
Exclude HTTP headers - This specifies whether the HTTP response headers should be excluded from the check.