Pieces with standard connections can be classified unambiguously by finding the longest string of knobs and labelling them in a counter-clockwise fashion. Pieces are named as follows:
4-knob.
3-knob-antiknob.
2-knob-2-antiknob.
knob-antiknob-knob-antiknob.
knob-3-antiknob.
4-antiknob.
Other important classes of peices are:
borders.
And finally the pieces with non-standard connections are known as the
weird beards.