About PL/SQL Identifiers

Every PL/SQL subprogram, package, parameter, variable, constant, exception, and explicit cursor has a name, which is a PL/SQL identifier.

The minimum length of an identifier is one character; the maximum length is 30 characters. The first character must be a letter, but each later character can be either a letter, numeral, dollar sign ($), underscore (_), or number sign (#). For example, these are acceptable identifiers:

X
t2
phone#
credit_limit
LastName
oracle$number
money$$$tree
SN##
try_again_

PL/SQL is not case-sensitive for identifiers. For example, PL/SQL considers these to be the same:

lastname
LastName
LASTNAME

You cannot use a PL/SQL reserved word as an identifier. You can use a PL/SQL keyword as an identifier, but it is not recommended. For lists of PL/SQL reserved words and keywords, see Oracle Database PL/SQL Language Reference.