Variable Fields

Individual fields:

Variable fields are called this because they can vary in content and length.  Some of these fields are simply ones that will display bibliographic information whenever a record is accessed.  Other variable fields are considered access points which are indexed to make the information contained inside searchable by the computer. 

Each variable field is marked with a 3–digit tag.  This tag identifies the type of data that is allowed in the field. The tag is then followed by two positions called indicators.  They are referred to as the 1st indicator and the 2nd indicator.  Each of these two indicators is coded according to the rules specified for the field.  Inside each field are subfields which are preceded by delimiters (represented Sierra with a pipe =| and represented in OCLC with a double dagger = ǂ) followed by subfield codes. Subfield codes are typically one lowercase letter although they can be numbers occasionally.  The subfield code follows the delimiter, both of which are preceded by punctuation that is specific to the subfield as determined by the field in which it is located, with a space between the punctuation and the delimiter. 

As with the fields themselves these subfields identify a specific part of the type of data in a field.  The codes for the indicators and subfields along with all the rules that apply to each tagged field can be accessed by right clicking on the field in OCLC and selecting “Marc Field Help” from the drop–down menu.

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