Yes the FACET designations where born out of the SIMJET Turbine model no. the airframes where designed for. It was a very simple way of designating thurst to airframe matches.

i.e.- 1200 = 12# thrust, 2300 = 23 # thrust.

One other note, the FACET-1200 will most certainly be a favorable match for the upcoming SIMJET-700. (and NO, I won't be re-designating the FACET-1200 to 700.