[1000mp] Question about Mk V Field

[Morel 4X1AD]

One of my friends just bought a FT1000MP Mk V Field. When transmiting, the
digital meter shows deviations on three bargraph lines:  Pout , Comp/ALC and
the third is marked "IDBS". This third line doesn't exist in my classic MP
and it's not explained in the Field's User Manual. What means this IDBS
metering (not IDBT) and where can be found in the manual ?

 

73

Morel

4X1AD