13.3 Identifiers
Identifiers are used as names. Identifiers are case insensitive.
Syntax
identifier ::= identifier_letter {[underline] letter_or_digit}*
letter_or_digit ::= identifier_letter | digit

An identifier shall not be a reserved word.
For the lexical rules of identifiers, the rule of whitespace as token separator does not apply.  In other words, identifiers do not contain spaces or other whitespace characters.

Semantics
All characters of an identifier are significant, including any underline character.  Identifiers differing only in the use of corresponding upper and lower case letters are considered the same.
Legality Rules
An identifier must be distinct from the reserved words of the AADL.
Processing Requirements and Permissions
In a nonstandard mode, an implementation may support other upper/lower case equivalence rules for identifiers, to accommodate local conventions.
In non-standard mode, a method of implementation may accept identifier syntax of any programming language that can be used for software component source text.
Examples
   Count  X Get_Symbol  EthelynGarçon
   Snobol_4 X1Page_Count  Store_Next_Item  Verrűckt