[RTTY] What Does MMTTY really send?

[aflowers at frontiernet.net]

  I'm running some simulations with various contest exchanges against BER, along with the various USOS combinations that are possible.  I was reading the MMTTY manual and it says this about the TX tab:
"USOS-- turns on USOS on transmit. When you transmit a space, MMTTY also sends a LTR shift character." 
So, how does MMTTY encode this with the TX-USOS button clicked?
"W1ABC 599 05 05 NY NY"
I'm wondering if someone knows off hand so I don't have to instrument it.  Reading the help file literally, it would be this:
<LTR>W<FIG>1<LTR>ABC<SP><LTR><FIG>599<SP><LTR><FIG>05<SP><LTR><FIG>05<SP><LTR>NY<SP><LTR>NY
...where <SP> = space and the LTRS and FIGS are the shift characters.  The LTR/FIG sequence seems kinda crazy, but I'd like to know for sure so I can simulate what really out there in the wild. 
Thanks,
Andy K0SM/2