In case of differences the FCOM has precedence over the FCTM.
We operate under EU-OPS and the FCTM states:
" 737-300 : Flaps 15,30 (for noise abatement ) and 40 are the normal landing positions. Flaps 15 is normally limited to airports where approach climb performance is a factor.
737-NG : Flaps 15 ( except JAA ), 30 (for noise abatement) and 40 are normal landing positions....'
Interesting difference between Classic and NG.
The FCOM for the Classic has no limitation for Flap 15 but the NG has : " Flap15 normal landings are prohibited. A flap 15 landing may be performed when required by a non-normal procedure"
So, with a 300 can be done , but not with a 700? Interesting..