A four-character sequence that identifies the suggested use for an element. Compare kind.
a case-sensistive sequence of alphanumeric characters, whose definition can be tested or specified
a null-terminated sequence of characters
a (possibly empty) sequence of non-space, non-tab, nonzero bytes
a sequence of one or more characters, starting with a letter or an underline, and continuing with zero or more letters, digits, underlines or hyphens