The four general parameters or characteristics of a sign are:
1. Handshape
2. Location
3. Movement
4. Orientation (palm orientation)
A fifth parameter that is often added to this list is
5. "Facial Expressions" and/or "Non-manual
Markers."
Facial expressions fall under the more general category of "non-manual markers" (NMM). Non-manual markers consist of
the various facial expressions, head tilting, shoulder raising, mouthing,
and similar signals that we add to our hand signs to create meaning.
Note if you are taking a test and are asked, "What are the four
characteristics or parameters of a sign?" Answer: handshape,
location, movement, and palm orientation.
What if you are asked "What are the
five characteristics or parameters of
a sign?" Then add "facial expressions" to your answer.