chunk of a RIFF file has a RIFF form tag; the first four bytes of chunk data are a FourCC that specify the form type and are followed by a sequence of subchunks. In the case of a WAV file, those four bytes are the FourCC WAVE. The remainder of the RIFF data is a sequence of chunks describing the audio information. The advantage of a tagged file format is that the format can be extended later without confusing existing file readers. The rule for a RIFF (or WAV) reader is that it should ignore any tagged chunk that it does not recognize. The reader won't be able to use the new information, but the reader should not be confused. The specification for RIFF files includes the definition of an INFO chunk. The chunk may include information such as the title of the work, the author, the creation date, and copyright information. Although the INFO chunk was defined in version 1.0, the chunk was not referenced in the formal specification of a WAV file. If the chunk were present in the file, then a reader should know how to interpret it, but many readers had trouble. Some readers would abort when they encountered the chunk, some readers would process the chunk if it were the first chunk in the RIFF form, and other readers would process it if it followed all of the expected waveform data. Consequently, the safest thing to do from an interchange standpoint was to omit the INFO chunk and other extensions and send a lowest-common-denominator file. There are other INFO chunk placement problems. RIFF files were expected to be used in international environments, so there is CSET chunk to specify the country code, language, dialect, and code page for the strings in a RIFF file. For example, specifying an appropriate CSET chunk should allow the strings in an INFO chunk (and other chunks throughout the RIFF file) to be interpreted as Cyrillic or Japanese characters. RIFF also defines a JUNK chunk whose contents are uninteresting. The chunk allows a chunk to be deleted by just changing its FourCC. The chunk could also be used to reserve some space for future edits so the file could be modified without being rewritten. A later definition of RIFF introduced a similar PAD chunk. RIFF WAVE The toplevel definition of a WAV file is: <WAVE-form> → RIFF('WAVE' <fmt-ck> // Format