A.3 ATIn commands
There are no universal standards for ATI commands. However, it is recommended that Plug and Play modems include an ATI9 command. If implemented, the modem shall respond to this command by returning information text at the same speed and parity as the ATI command.
That information text should include all the characters it would deliver in a complete Plug and Play ID character string, in standard ASCII. However, if a modem manufacturer implements an ATI9 command, that format may be adjusted for accessibility. The two character PNP ID could be converted to a legible string (e.g. "1.00"). Also, <CR>,<LF> pairs could be inserted. The checksum is optional.