MARC Review: Subfield Code patterns

SUBFIELD PATTERNS

When more than one subfield code is entered into the 'SUBF' box, the program now assumes you want to search for matching subfield code patterns. This function is useful for research, troubleshooting, and finding examples of patterns of subfield code usage. For example, if you enter 245 in the TAG box and 'ahb' (without the quotes) in the SUBF box, the program will match all records where the 245 field contains subfield codes $a, $h, $b (in that order).

A subfield code pattern will match fields that contain additional subfields as long as the specified subfield codes are present in the specified order. For example, these patterns will match: $a $h $b (exact match of the pattern), $6 $a $h $b, and $a $h $b $c (because $a $h $b are present in the specified order); but 245 fields containing subfield codes like $a $b $h (in that order) will not match (because '$b $h' does not in the specified order), nor will 245 fields containing subfield codes $a $n $h $b (because the $n breaks the specified pattern).

Hint: To force a more literal match, enclose the subfield code pattern in quotes. For example, in X10, a search for 'an' (without the quotes) will match many headings with a $b between the $a and $n. But if we enter 'an' (with the quotes) in the SUBF box, the program will not match fields with the $a $b $n pattern; it will only find fields with a $n immediately after the $a.

NOTES Enclosing the subfields in quotes will pop-up a form validation error; you can bypass this warning by right-clicking on the 'Subf' label (to the left of the box) and responding to the prompt. Also, enclosing subfields in quotes is the only way to match subfield code patterns where any subfields in the pattern are repeated. For example, to find cases of $a $b $b $c in the 260, you must enter 'abbc' (with the quotes); entering 'abbc' (without the quotes) will effectively be treated as if it were 'abc'. Finally, if you also enter a pattern in the DATA box, the program will match that pattern in any of the subfields specified above.