[fpc-pascal] specialize, identifier not found

[Santiago A.]

Type
 TRegAlias=record
    ...
 end;
 
 TArrayAlias=specialize TArray<TRegAlias>; // <==== Error here   

defconexion.pas(71,14) Error: Identifier not found "specialize"
defconexion.pas(71,25) Error: Error in type definition
defconexion.pas(71,25) Fatal: Syntax error, ";" expected but "identifier
TARRAY" found


Why this error?
Why does the compiler try to look for a Identifier "specialize" instead
of interpreting it as a reserved word?

-- 
Saludos
Santiago A.