Character encoding generally treats the umlaut and the diaeresis as the same diacritic mark. The "diaeresis" and the "umlaut" are diacritics marking two distinct phonological phenomena. Another diacritic used in Greek is the diaeresis (), indicating a hiatus. Sometimes, there's a need to distinguish between the umlaut sign and the diaeresis sign. Dutch uses the acute accent to mark stress and the diaeresis (trema) to disambiguate diphthongs/triphthongs. These two diacritics originated separately; the diaeresis is considerably older. The diaeresis was abolished by the last Orthography Agreement. For "deity" and "deify", only solid styling (no hyphen or diaeresis) is normative. The latter elision spans the diaeresis in the last line. In French, in the aforementioned cases the diaeresis is usually written over the following vowel. Accents are written above a diaeresis or between its two dots. Languages such as Dutch, Catalan, French, Galician and Spanish make regular use of the diaeresis. No spaces are written between them, and a diaeresis is added when necessary. The word "diaeresis" is from Greek (), meaning "division", "separation", or "distinction". Since either use is superfluous, the diaeresis was frequently omitted by Tolkien.