The Language interface implies that the ID3v2 frame supports its content to be given in multiple languages.

The three byte language code is used to describe the language of the frame's content, according to ISO-639-2. The language should be represented in lower case. If the language is not known the string "xxx" should be used.

• author: Sven Vollbehr <svollbehr@gmail.com>
• version: $Rev: 64 $
• copyright: Copyright (c) 2008 The PHP Reader Project Workgroup
• license: New BSD License

Located in /ID3/Language.php (line 54)