Actually, what the document says (maybe not too clear) is that when you send in an object that has guarded attributes, and you have defined them different than what the files say, the object WILL be updated, BUT all guarded attributes will be reset to their "guarded" value.
Ok, sounds reasonable. Let me suggest a change (addition to the last part of the paragraph) to the text along the lines of: If an update is sent to the database software using another mechan- ism (i.e. mail to auto-dbm@ripe.net) that contains a guarded attri- bute, this will not be allowed to change the guarded attribute. If the value of the attribute is the same as what is currently registered in the database then no warnings will be given. However, if the update contains a value for a guarded attribute that is dif- ferent to that registered in the database, a warning will be sent to the originator and the guarded value will remain unchanged. Any changes of other (unguarded) fields in the update will be checked for syntactic correctness and if they pass will go through to the database irrespective of any conflicts for the guarded fields. - Havard