`@samp'
Indicates text that is a literal example of a sequence of
characters.
`@kbd'
Indicates the names of keys on the keyboard or characters you
type.
`@key'
Used for the conventional name for a key on a keyboard.
`@var'
Indicates a metasyntactic variable.
`@dfn'
Indicates the introductory or defining use of a term.
`@cite'
Indicates the name of a book.
[I left @file out of HTML -- can't remember why.]