An electronic white pages links various devices, like computers and telephones, to an individual or organization. Various attributes such as X.509v3 digital certificates for secure cryptographic communications are captured under a schema, and published in an LDAP or X.500 directory. Changes to the LDAP standard are managed by working groups in the IETF, and changes in X.500 are managed by the ISO. The ITU did significant analysis of gaps in digital identity interoperability via the FGidm, focus group on identity management.