Oracle Message PLW-05004 - identifier string is also declared in STANDARD or is a SQL builtin

ERRORidentifier string is also declared in STANDARD or is a SQL builtin
CAUSEThe indicated identifier was also either: o) declared in package STANDARD, or o) a SQL builtin function, or o) a pseudo-column. This situation can result in name resolution issues since the STANDARD/builtin declaration will be chosen over the local declaration in SQL statements; however the local declaration will be chosen over the STANDARD/builtin declaration outside SQL scope. (See the documentation on PL/SQL name resolution.)
ACTIONEither: o) rename the given identifier, o) qualify any references to the identifier with the containing scopes name, or o) make sure the intended resolution occurs if using the identifier in SQL scope.