The type xs:NMTOKEN represents a string that contains no whitespace. xs:NMTOKEN values may consist only of characters allowed in XML names, namely letters, digits, periods, hyphens, underscores, and colons. For example, navy, 123, and SENDER_OR_RECEIVER are all valid values. Leading and trailing whitespace is allowed but is considered insignificant.

Because xs:NMTOKEN is ultimately derived from xs:string, xs:NMTOKEN values can be compared and used like strings.