The Match Rules form is the heart of the PLP process.
The Match Rules define:
the primary keys that are searched in the database,
the crosschecks that are run whenever two records match on a primary key,
the preferences that are used to determine the best matching record when multiple records match and pass all the crosschecks,
the special crosscheck options that are used to modify crosscheck behavior,
the redirection rules that are used to divert records that fail crosschecks from the XCFails file (and thus decrease the amount of human review that is needed), and
the synonym rules that are used to increase the number of matches by equivalencing slightly differing strings in phrases that occur in the MARC data and cause crosschecks to fail.
Configuring a set of match rules is described in the following sections:
1. Record Matching Rules (Primary keys, Crosschecks, Preferences)
2. Crosscheck Options
3. Redirection Rules
4. Synonyms
5. Special rules and exceptions