Once, long long time ago, there was a nice little network used exclusively by airlines and it's partners and this network was names S.I.T.A. (short for Societe International de Telecommunications Aeronautique).

On this site you will find some old documents and pictures. If you have more I would love to hear from them!

A lot of information about the world famous Sitatex package

a very early incarnation of the SITA Type-B network:

A high level network (HLN) routing chart:

A later incarnation from the complete network:

A form used to write down a Type-B message: