In a white pages directory, each entry typically represents an individual person that makes use of network resources, such as by receiving email or having an account to log into a system.
While many telephone service providers have for decades published a list of their subscribers in a telephone directory, and similarly corporations published a list of their employees in an internal directory, it was not until the rise of electronic mail systems that a requirement for standards for the electronic exchange of subscriber information between different systems appeared.
A white pages schema typically defines, for each real-world object being represented: One of the earliest attempts to standardize a white pages schema for electronic mail use was in X.520 and X.521, part of the X.500 specifications, that was derived from the addressing requirements of X.400 and defined a Directory Information Tree that mirrored the international telephone system, with entries representing residential and organizational subscribers.
One of the most widely deployed white pages schemas used in LDAP for representing individuals in an organizational context is inetOrgPerson, defined in RFC 2798, although versions of Active Directory require a different object class, User.
Many large organizations have also defined their own white pages schemas for their employees or customers, as part of their Identity management architecture.