'ATA Spec 100[1]' and iSpec 2200[2] are information standards for aviation maintenance and flight operations[3] published by Airlines for America (formerly Air Transport Association).
[4] These standards provide recommended specifications for the content, structure and deliverables to meet communication requirements [physical, electronic and future technology] of aircraft product technical information.
It established an industry-wide numbering scheme to organize aviation technical documentation as well as content and formatting guidelines for its conventional printed distribution.
ATA Spec 2100 focused on electronic data exchange implemented in SGML.
It incorporates the previous 100 and 2100 specs which won't be maintained beyond their final 1999 revisions.