The word '' : tréma , used in linguistics and also , is from the Greek trē̂ma τρῆμα and means a 'perforation', 'orifice', or 'pip' as on , thus describing the form of the diacritic rather than its function.
In addition, there are codepoints for dozens of as shown above, mainly for compatibility with older character encodings.
Ë, ë e-diaeresis is a letter in the Albanian, Kashubian, Emilian-Romagnol, Ladin, and Lenape alphabets.
A range of are encoded in Unicode; the technique is needed to produce others.