001 (records from OCLC)
035 (records from other sources)

For a history of the OCLC number, please refer to OCLC's Technical Bulletin No 253.

• Check 001 for a field beginning: 'ocl', 'ocm', or 'ocn' (assumes 001 is not repeated);
• Check all 035s for a field beginning '$a(OCoLC)[0-9]';

Take the first matching field found (thus 001 takes precedence over 035).

Leading zeroes and prefxes are ignored during comparison.

Each OCLC number is queried three different ways ('n' is a non-zero digit):

1. OCOLC nnnnnn
2. OCOLC 00nnnnnn
3. OCOLC OCMnnnnnn

Matching stops if the number of records retrieved exceeds 'Max Numeric Hits'