Sorting
In a title catalog, one can distinguish two sort orders:
- In the grammatic sort order (used mainly in older catalogs), the most important word of the title is the first sort term. The importance of a word is measured by grammatic rules; for example, the first noun may be defined to be the most important word.
- In the mechanic sort order, the first word of the title is the first sort term. Most new catalogs use this scheme, but still include a trace of the grammatic sort order: they neglect an article at the beginning of the title.
The grammatic sort order has the advantage that often, the most important word of the title is also a good keyword (question 3), and it is the word most users remember first when their memory is incomplete. However, it has the disadvantage that many elaborate grammatic rules are needed, so that only expert users may be able to search the catalog without help from a librarian.
In some catalogs, person's names are standardized, i. e., the name of the person is always (catalogued and) sorted in a standard form, even if it appears differently in the library material. An advantage of the standardization is that it is easier to answer question 2 (which works of some author does the library have?). On the other hand, it becomes more difficult to answer question 1 (does the library have some specific material?) if the material spells the author in a peculiar variant. For the cataloguer, it may incur (too) much work to check whether Smith, J. is Smith, John or Smith, Jack.
For some works, even the title can be standardized. For example, translations and reeditions are sometimes sorted under their original title. In many catalogs, parts of the Bible are sorted under the standard name of the book(s) they contain.
Many detail questions about alphabetic sorting of entries arise. Some examples:
- Some languages know sorting conventions that differ from the language of the catalog. For example, some Dutch catalogs sort IJ as Y. Should an English catalog follow this suit? And should a Dutch catalog sort non-Dutch words the same way?
- Some titles contain numbers, for example Orwell's 1984. How to sort them? (Often, it is decided to sort it as Nineteenhundred eighty-four.)
- de Balzac, Honoré or Balzac, Honoré de? Ortega y Gasset, José or Gasset, José Ortega y?
In a subject catalog,
one has to decide on which 
