Who Puts a Lot of Information in Directories?. Most directories don't contain much information. They contain people data -- user names, associated credentials (hashed password, X.509 certificate), addresses (email, physical, telephony, etc.); group data -- lists employed to associate roles and permissions with people or as email distribution lists; and sometimes also server/service (physical and logical) data. And that's just about it.

There are exceptions, however. The notable ones seem to be:

... David Ferris, with thanks to Nick Shelness and Persistent Systems' Sameer Karmarkar