Convention when showing orchid "parents"

[fredfarmer]

Many vendors will show both the "parents" of new hybrids when they are listed for sale. Makes good sense as the progeny will differ from the parents just as children differ from their parents and from each other. My question is, is there a convention as to which parent goes where - when side-by-side - is the male/pollen donor always on the left or right? Analagously, when one-is-on-top of the other - is the male/pollen doner on the top or the bottom. Or is it all random?