Hans,
I suspect that Ralf is referring to -
FR: Get/set Transmit VFO Mode: 0 = VFO A; 1 = VFO B; (2 = Split only for Set)
FT: Get/set Receive VFO Mode: 0 = VFO A; 1 = VFO B; (2 = Split only for Set)

However the full description in your response clears things up.
FR relates to Receive settings  and FT relates to Transmit settings.
I think a simple typo crept into the command listing near the head of your original post.
73 Fred VK2WS