The use of both, however, is considered to be largely archaic. The diaeresis mark is sometimes used in English personal first and last names to indicate that two adjacent vowels should be pronounced separately, rather than as a diphthong. Examples include the given names "Chloë" and "Zoë", which otherwise might be pronounced with a silent "e". To discourage a similar mispronunciation, the mark is also used in the surname "Brontë". It may be used optionally for words that do not have a morphological break at the diaeresis point, such as "naïve", "Boötes", and "Noël". However, it is now far less commonly used in words such as "coöperate" and "reënter" except in a very few publications—notably "The New Yorker" and "MIT Technology Review" under Jason Pontin. Germanic umlaut is a specific historical phenomenon of vowel-fronting in German and other Germanic languages. In German it causes back vowels , and to shift forward in the mouth to , and , respectively. In modern German orthography, the affected graphemes , and are written as , and , i.e. they are written with the diacritical mark "umlaut", which looks identical to the "diaeresis" mark. German phonological umlaut was present in the Old High German period and continued to develop in Middle High German. From the Middle High German period, it was sometimes denoted in written German by adding an "e" to the affected vowel, either after the vowel or, in small form, above it. This can still be seen in some names, e.g. Goethe, Goebbels, Staedtler. In medieval German manuscripts, other digraphs were also commonly written using superscripts. In "bluome" ('flower'), for example, the was frequently placed above the ("blůme"). This letter survives now only in Czech. Compare also for the digraph "nn", with the tilde as a superscript . In blackletter handwriting as used in German manuscripts of the later Middle Ages, and also in many printed texts of the early modern period, the superscript still had a form that would be recognisable to us as an , but in manuscript writing, umlauted vowels could be indicated by two dots since the late medieval period. In the forms of handwriting that emerged in the early modern period (of which Sütterlin is the latest and best-known example) the letter was composed of two short vertical lines very close together, and the superscript looked like two tiny strokes.