Letter-like form with built-in value.
Interpreted by default as the symbol Degree.
30 is interpreted as 30 Degree.
The symbol is sometimes used in mathematics to indicate the interior of a set.
Not the same as \[SmallCircle] or \[EmptySmallCircle].
See The Mathematica Book: Section 1.10.4 and Section 3.10.3.
See also: \[Prime] , \[DoublePrime] .