Hide from address book true/false ?

Dear all,
I am running a report which will show all user accounts with a mailbox store and which ones of these have the attribute "Hide from address book". The output from the report shows "Hide from AB = True" for accounts with hidden mailbxoes as expected, but the remainder show a mixture of False and nothing in the field. Does anybody know what the difference between false and a blank fields could be ?
Many thanks
Howard

[kstanush]

Re: Hide from address book true/false ?

The ones with the missing field would have the default value, which is probably FALSE. AD can't store blank values, and when something is added to the schema, AD does not add the new attribute(s) to all of the objects. So anything where you have not actually set a value will not have the attribute at all.