Alphanumeric Paging Entry Protocol:, a brief document that outlines the IXO protocol.

IXO Mailing List FAQ:, a FAQ about an IXO mailing list and the IXO protocol, all wrapped into one.

Pager Hardware Reprogramming and Paging Protocols: For those who like to get into the guts of pagers, here's some more information on paging protocols, pager programming and pager hardware.