Bukkit/CraftBukkit — comment on commit 44b59dd7e560fe434c374a12f2224fedf1ea7e46
File:  line 0
By NobodysNightmare:

just FYI, you do not need a modded client. Prior 1.1, you could not type "ß" (german umlaut), but since 1.1 you can type it, but it does not get sent.

However this observation was only made by looking at the chat, not by looking at the actual packets