The ATN SARPs have been developed as a five part document, as below. If you download any of these documents, you should note these are editors' drafts and not the approved ICAO text. No warrantee is offered as to the correctness of these documents and those needing to claim compliance against the ICAO SARP must obtain the official text from ICAO when it is published. The versions available here in no way replace the official ICAO text. Please note that these documents are in Adobe Acrobat format.