Vowel elision occurred to prevent vowel clusters. Syncope is the elision of vowels between consonants. Gemination also occurs in case of schwa elision. An apostrophe may be used for vowel elision or crasis. Long vowels are usually the result of the elision of guttural consonants. Finally, processes of vowel elision occur. Class adjectives also experience vowel changes when subject to the elision described above. They are categorised into different classes based on the phoneme which undergoes elision. For further information about final vowel elision, see Elision (French). It, too, underwent vowel elision, and came to be pronounced as and then . By means of vowel elision, "domnia" became shortened to "dumnea". The latter elision spans the diaeresis in the last line. Voiced stops may have been the result of rules of allophony, elision, or sandhi. Some nonstandard dialects, such as Satsuma-ben, are known for their extensive elision. Optimization techniques used include inlining, elision of expensive runtime properties, and inline caching.