The pattern-action file consists of a series of patterns and associated actions.
The pattern-action file contains the rules for standardization; that is, the actions to execute with a given pattern of tokens. After the input record is separated into tokens and classified, the patterns are executed in the order they appear in the pattern-action file.
A pattern either matches the input record or does not match. If it matches, the actions associated with the pattern are executed. If not, the actions are skipped. In either case, processing continues with the next pattern in the file.