On Fri 10 Jan at 19:45 Hamish Moffatt (3:632/552{at}fidonet) wrote to Alex Mcconnell:

 HM> "Full Hayes AT command set" is a misnomer these days. Only 
 HM> Hayes could claim such a thing. None of the commands for any 
 HM> of the post-2400 commands have ever been standard. Even 
 HM> then, the S registers were never completely standard. These 
 HM> days, most Rockwells will have the same commands between 
 HM> them, except those with souped up ROMs (Supra, etc). USR, 
 HM> and GVC (KTX) have different commands because they use 
 HM> different chips and ROMs. Same with NetComm MxF, etc.

Check ITU-T Recommendation V.25ter... this is the "recommended
(-:" way to use basic and extended AT commands.
 
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