You might be right about the USR 9600 bps mode, but for certain their original 14.4k bps mode was proprietary and named "HST." I still fondly remember when I got my Courier HST and witnessed its intense speed boost versus my prior 2400 bps modem.
There were 9600 bps USR Courier HST models. Pretty sure I still have one up in the attic unless I've tossed it. I forget what I had in the 14K generation.
Maybe I am misremembering, then. Perhaps I had a 9600 bps HST.