Forming Identifiers

Valid Characters

An identifier consists of a combination of the following:

Letters (A through Z and a through z)—See Delimited Identifiers for information about the significance of lowercase and uppercase letters
Digits (0 through 9)
At sign (@)
Dollar sign ($)
Pound sign (#)
Underscore (_)

The first character of an identifier must be a letter, @, $, or #.

Maximum Length

The maximum length of a given identifier is presented in Syntactic Limits.