@Caimarvon and @Draconis made simple work of what's an absolute mystery to people like my family and I, who are only amateur linguists in the same way that pushing an apple onto a stick could be thought a wheel. Their insight led me to Diacritics for medieval studies by Marc Wilhelm Küster and Isabel Wojtovicz, which explained the Combining Latin Small Letter E diacritical mark (among many others).
The handling of medieval characters in the context of IT systems is problematic, especially as far as data exchange and publication in electronic media is concerned.
There is as yet no reasonably complete list which covers all characters and special symbols used in modern editions of medieval texts. In particular, there is no complete coverage of the many abbreviatures that are typical for medieval manuscripts and no study on the applicability of the character-glyph-model in this context.
This paper concentrates on one special aspect of characters in medieval studies, namely super-script letters which are used as diacritics, e. g. uͤ. These we shall call superscript letter diacritics. While it also cannot claim completeness, it covers the superscript letter diacritics which occur in major medievalistic internet projects and in a selection of important editions. It concentrates exclusively on modern editions of medieval literature and on grammars of Middle High German.
The by far most frequent case is that of superscript vowels (and c). According to (Reichmann,1993) there can be the following letters with a superscript:
- aͦ, aͤ, aͨ, aͧ, aͮ
- oͨ, oͤ, oͮ
- uͨ, uͤ, uͦ, uͥ
Most of these represent different pronunciations of the base vowel, usually, but not always, pronunciations that are in between the base vowel and the vowel which is indicated by the superscript, be the result a diphthong or an umlauted letter. Thus we can have uͦ for the /uo/ diphthong or uͤ for u umlaut.
The most frequent superscript letter diacritic is the superscript e (e) which usually designates an umlauted letter. It is regularly used in medieval texts. In modern editions it occurs very frequently in the Middle High German parts, whereas text in modern German e. g. in the annotations which appear on the same page is never written this way. Thus we can have words like »roͤmische riche« (Roman empire) and »zuͦversuͤnende« (confident) on the same page as »Übersetzer«, »übersetzt«, »sinngemäß«, »läßt« etc. Such examples can be found by the hundred, e. g. also in grammars:
So wird der Umlaut von /a/→/e/ z. T. gar nicht bezeichnet oder als〈e, ę, ei, ä, aͤ〉 angegeben, der des /a̅/→/æ/ als 〈æ, œ, ê, e〉.
In spite of this, Middle High German and modern German parts on one page are almost always typeset in the same base font. Font switching is highly unusual.
The superscript letter diacritic o is in the two hundred years of typesetting in this field distinctly regarded as an o typographically, not as a ring above. Thus only zuͦ, not zů, would be an acceptable rendering of the /uo/-diphthong.
To summarize, all of combinations of base letters with the superscript letter diacritics a, c, e, i, o, u, v modify the sound value of the base letter in a significant and predictable way. These diacritics were a regular part of both the original Middle High German orthography and (more importantly) of current editorial practice in the complete field of medieval studies and German dialectology. Since quite a number of these projects also are active in electronic data processing and have an urgent need to exchange data, e. g. via the World Wide Web, these are an absolute core set of combining diacritics.