Versions, flavors, and DOCTYPE

There are three current flavors of both HTML 4 and XHTML 1.0: strict, transitional, and frameset. In an attempt to separate structure from formatting, the W3C has been earmarking some elements for eventual removal from the specifications. (X)HTML strict is characterized by its prohibition of these so-called deprecated tags. The only difference between transitional and frameset, both of which consider deprecated tags to be valid, is that the latter allows frames (which we discuss in Chapter 15, Frames).