Fractions should always be hyphenated when used as adjectives. The two terms were now compound nouns often shown hyphenated. Systematic names and words comprising SI prefixes and binary prefixes are not hyphenated, by definition. Words containing non-technical numerical prefixes are usually not hyphenated. Some couples keep their own last names but give their children hyphenated or combined surnames. Not all hyphenated surnames are the result of marriage. There is some confusion over whether these prefixes should be hyphenated and/or in upper case. Word divisions are generally disjunctive, with clitics written as separate words (not hyphenated). Compound verbs in British English are hyphenated more often than in American English. The names are hyphenated together, using en dashes where possible. Court-martial is hyphenated in US usage, whether used as a noun or verb. Thus, professional identities have become hyphenated or hybridized to reflect this shift in work ethic. In terms of orthography, compound ranks were invariably hyphenated, prior to about 1980. The genus name has also been hyphenated as "Pseudo-tsuga". Sometimes the words are hyphenated; sometimes they are not.