Fig. 4.7.9 Different kinds of taxonomies.

Taxonomies—Maintenance Over Time

A final observation about taxonomies is that over time, taxonomies require maintenance.
Taxonomies require maintenance because language is constantly changing. For example,
in the year 2000, if you referred to a “blog,” no one would have known what you are
talking about. But 10 years later, the term “blog” is a commonly used term.

Over time, language and terms change. And as language and terms change, the
taxonomies that track those changes must be brought up to date.

Fig. 4.7.10 shows that over time, taxonomies require periodic maintenance.

Chapter 4.7: Taxonomies