Linking between records on basis of PPN’s is a feature of CBS that exists for several decades now. Thus, when we talk about links in this documentation, we mean the PPN links between records.
In the CBS MARC 21 cataloguing format, subfield $Z is used; in PICA+ the corresponding subfield is $9.
Kinds of links
Linking is a complex functionality of a CBS. Three kinds of links can be discriminated:
- Links between bibliographic and authority records, e.g. a name of an author of a book or article linked to an authority file1 of personal authors or a subject heading linked to an authority file of subject headings.
- Links between bibliographic records
- Part of a series linked to the record that describes the series as such.
- Part of a multivolume publication linked to the record that describes the multivolume as such.
- Links to related bibliographic records, e.g. translations, former titles, etc.
- Links to related bibliographic records e.g. on another carrier.
- Information concerning the host item for the constituent unit described in the record (vertical relationship). E.g. a link from an article to the serial, from a track to the cd on which the track is published.
- Links between authority records
- The “see also” links within the same authority file.
- The “see also” links between several kinds of authority files, e.g. a personal name linked to a corporate body (e.g. his/her employer) or to a topical term e.g. the topic in which a person is specialized in.
A special kind of links are those, that are used within the framework of IFLA LRM (Library Reference Model) between works, expressions and manifestations (and items).
Single linking means that there is one PPN link per field. This belongs to the ‘basic’ CBS features. But multiple linking, i.e. more than one PPN link per field, is also possible. Especially for CBS MARC 21 fields, this feature is important.
It is possible to use separate PPN links for next cases
- $v - Form subdivision
- $x - General subdivision
- $y - Chronological subdivision
- $z - Geographic subdivision
- Separate PPN link for the title portion in author (personal name, corporate name, meeting name)-title combinations