This was years ago. I must have had bad luck to have wanted to edit 'special' pages, that don't supply the code. I assumed that was the general rule, which the help page seemed to confirm:

> When no code word is given, you may use an alternative code word that floats along among trusted users. There is no way to apply for this code. Try your friends-of-friends network. Remember that this code and the mechanism itself will change if abused. http://c2.com/cgi/wiki?MoreAboutCodes

I just checked what you said, and the above seems to be (now?) the exception, and most pages do supply the code. A surprise to me, good to know, thanks!