== Different standards ==
A common stereotype within the library community is that catalogers care about nothing but following arbitrary rules about punctuation and other trivialities. Rules and standards do play a major role in cataloging today, and also allow catalogers to produce catalog records that can be shared, enriched, transformed, and displayed in powerful ways. However, as no rules will be truly universal in their application, catalogers are often called to exercise their judgement when existing standards and codes prove unsatisfactory.
A number of codes, controlled vocabularies, schemas, and protocols have roles to play in today's library catalogs. Furthermore, as libraries are becoming increasingly interested in providing electronic resources to their patrons, they are examining and implementing new ways of expressing bibliographic metadata. The table below offers a brief comparison of some of the standards used in describing two very different library collections.
Some of these standards, such as Dublin Core, LCSH, and MARC may be actively consulted by a cataloger as they describe a document for one of these collections, depending on how familiar they are with the standards, and how many similar documents they have cataloged. Other standards, such as UTF-8, Z39.50, and HTTP are built into software tools used by catalogers and essentially hidden while performing day-to-day cataloging. These latter standards generally only need to be consulted when creating new tools or troubleshooting existing ones.