The whole point of documentation is so that people who actually use the system can better understand the system they work with without having to trudge in the developer's programming mess(es). If documentation is not consistent, neither can be the developer who uses it.
The codex is some kind of a mess. General behavior is to let users (re)write it and then go over it and change what they (whoever this is) think. Ex. The Codex lacks a lot of functions in the function reference. On some places you already got the 3.1 explanations, on other completely outdated stuff. Sometimes you'll find two versions (current and future) or existing empty pages for template tags coming in the future.
If you have any questions, post them up on My Talk page!