Understanding architectural profiles

Here are the six mouldings that, with the addition of the band (flat profile), make up just about all profiles used in architecture and furniture.  

Notice the difference between cyma recta and cyma reversa where the latter is shaped to be used as a support - in fact all the mouldings other than cyma recta are supports so that the coma recta would be used at the top of a series of moulding for example on an entablature or cornice.

Architectural profiles