Gutenberg forced cataloguing to evolve from simple inventory tool to finding instrument. The first "modern" catalog is Bodley's dictionary catalog of 1620. Efforts to develop a taxonomy for all knowledge was catalyzed by Bacon's Advancement of Learning.

During the intervening centuries, various types of catalogs have been devised and promoted. Some schemes organized by form, others by discipline, yet others by author or title. Eventually, classified catalogs became very popular in Europe, but these catalogs required the user to be intimate with the hierarchy upon which they were arranged.

Alphabetico-classed was an attempt to simplify access for those library patrons not familiar with the hierarchical structure of the catalog. Materials are arranged first by the name of the general discipline, then further by the names of classes and subclasses, with no attempt to accommodate a subject classification system beyond the alpha arrangement.

During the 19^th century, pitched battles erupted to determine which scheme would emerge predominant. Alphabetico-classed was not among these. The three most popular versions of the modern catalog are:

Dictionary Catalog

A dictionary catalog files all headings--title, subject, references, etc., within a single alphabet.

Divided Catalog

A divided catalog is an adaptation of the dictionary catalog with some of the headings separated.

Classified Catalog

A classified catalog employs a systematic arrangement of subject headings supplemented by indexes
for the other categories, in alphabetical order.