isr.co.ro : glossary htm and html (HyperText Markup Language) Two suffixes applied to files names to indicate the content is formatted for use with the World Wide Web and compatible programs. The original "html" indicator came from the name of the HyperText Markup Language used for Web files, while the shortened form was added for computers running operating systems, such as Microsoft DOS (and older versions of Windows), that can accept only three-character file-name suffixes.