1. 1 Formal definition of the water vapour continuum in CKD / MTCKD model The "25 cm-1 plinth" of Lorentzian WM lines is not subtracted from continuum in CKD\MTCLD model in order to ensure "smooth" continuum. Line Continuum plinth 25 cm -1

2. 2 Formal definition of the water vapour continuum in CAVIAR model The "25 cm-1 plinth" of Lorentzian WM lines maybe should not be subtracted from CAVIAR continuum in order to ensure compatibility with most Line-by-Line codes

3. 3 Physical definition of in-band water vapour self-continuum in CAVIAR model Physical parameters: bound 25-30cm -1 ; S i bound (currently from Kjaerg. et al., later on UCL) ; metast. 10 cm -1 ; 2 S i monomer (until an initio calc. available) ; K eq bound (T); Q metast. /Q bound (T) …