meaning of header entries in cst export file

Hi,
does someone of you knows what is the meaning of Left or Right in the following cst-antenna-export txt-file ?
Theta [deg.] Phi [deg.] GainAbs [dB ] GainTh [dB ] GainPh [dB ] Left [dB ] Right [dB ] Phase(ETh)[deg.] Phase(EPh)[deg.]
thanks !
br

My guess is that this is the gain for circular polarization (left hand and right hand).