This is documentation for Mathematica 3, which was
based on an earlier version of the Wolfram Language.
View current documentation (Version 11.2)
 Documentation / Mathematica / The Mathematica Book / Reference Guide / Input Syntax  /

A.2.4 Symbol Names and Contexts

Symbol names and contexts.

Symbol names and contexts can contain any characters that are treated by Mathematica as letters or letter-like forms. They can contain digits but cannot start with them.