Intent Language 3.0 constructs are incompatible with Intent Language 2.0 and earlier versions. The first line of a source file contains a version identifier to allow both Intent Language 3.0 and Intent Language 2.0 versions to be read and compiled. An Intent Language 3.0 file will be rejected by an Intent Language 2.0 product. Intent Language 2.0 files may be accepted by Intent Language 3.0-compliant applications, but are not required to do so.