Unicode (unencoded) or string. Internally everything is a unicode string.
Integers and floats are interchangable in FontParts (unless the specification states that only one is allowed).
An immutable iterable contaning two Integer/Float representing:
define the angle specifications here. Direction, degrees, etc. This will always be a float.
A String following the UFO identifier conventions.
An immutable iterable containing four Integer/Float representing:
Values are from 0 to 1.0.
An immutable iterable defining a 2x2 transformation plus offset (aka Affine transform). The default is (1, 0, 0, 1, 0, 0).
This must be an immutable, ordered iterable like a tuple.