also have compounds. They are created by combining two or more sign stems. So-called "classical compounds" are compounds derived from classical Latin or ancient Greek roots. Formation of compounds Compound formation rules vary widely across language types. In a synthetic language, the relationship between the elements of a compound may be marked with a case or other morpheme. For example, the German compound consists of the lexemes (sea captain) and (license) joined by an -s- (originally a genitive case suffix); and similarly, the Latin lexeme contains the archaic genitive form of the lexeme (family). Conversely, in the Hebrew language compound, the word בֵּית סֵפֶר (school), it is the head that is modified: the compound literally means "house-of book", with בַּיִת (house) having entered the construct state to become בֵּית (house-of). This latter pattern is common throughout the Semitic languages, though in some it is combined with an explicit genitive case, so that both parts of the compound are marked, e.g. Arabic عبد الله ʕabd-u l-lāh-i (servant-NOM DEF-god-GEN) "servant of-the-god: the servant of God". Agglutinative languages tend to create very long words with derivational morphemes. Compounds may or may not require the use of derivational morphemes also. In German, extremely extendable compound words can be found in the language of chemical compounds, where, in the cases of biochemistry and polymers, they can be practically unlimited in length, mostly because the German rule suggests combining all noun adjuncts with the noun as the last stem. German examples include (color television set), (radio remote control), and the often quoted jocular word (originally only two Fs, Danube-Steamboat-Shipping Company captain['s] hat), which can of course be made even longer and even more absurd, e.g. Donau­dampfschifffahrts­gesellschafts­kapitänsmützen­reinigungs­ausschreibungs­verordnungs­diskussionsanfang ("beginning of the discussion of a regulation on tendering of Danube steamboat shipping company captain hats") etc. According to several editions of the Guinness Book of World Records, the longest published German word has 79 letters and is Donau­dampfschiffahrts­elektrizitäten­hauptbetriebswerkbau­unterbeamten­gesellschaft ("Association for Subordinate Officials of the Main Electric[ity] Maintenance Building of the Danube Steam Shipping"), but there is no evidence that this association ever actually existed. In Finnish, although there is theoretically no limit to the length of compound words, words consisting of more than three components are rare. Even those with fewer than three components can look mysterious to non-Finnish speakers, such as (emergency exit). Internet folklore sometimes suggests that (Airplane jet turbine engine auxiliary mechanic non-commissioned officer student) is