4. Document type detection

This chapter covers Introduction to MIME types Working with MIME types in Tika Identifying file formats

Let’s talk about taxonomy. Taxonomy is the science of classification. Taxonomies are used to identify and classify concepts in order to better understand them and to have a shared vocabulary for describing things. For example, the Linnaean taxonomy^[1] is the classical system of naming all biological organisms using two-part Latin names that identify both the genus or category and the specific species within that category. The term Homo sapiens identifies the modern human species as a part of the family of earlier human-like species, along with the extinct Homo neanderthalensis. A similar taxonomy, called the internet media type system, is used to identify digital document formats.

^[1] Carl Linnaeus, a famous Swedish scientist, wrote Systema Naturae in 1735, in which he describes and categorizes plants, animals, and minerals. The seminal work was one of the first widely known uses of rank-based classification, in which certain categories can be ranked higher or lower than others. In Linnaeus’s taxonomy, plants, animals, and minerals are first ranked by class, then by order, and then by species. Relating back to this chapter, the IANA’s (Internet Assigned Number Authority’s) classification of internet media types mentioned in section 1.1.1 is a modern example of a rank-based classification system. MIME types are broken down into top-level categories, then specialized as subtypes within those categories.