The glyph is a canonical composition of the glyphs Glyph for U+004FLatin Capital Letter O, Glyph for U+0308Combining Diaeresis. It has no designated width in East Asian texts. In bidirectional text it is written from left to right. When changing direction it is not mirrored. The word that U+00D6 forms with similar adjacent characters prevents a line break inside it. The glyph can be confused with one other glyph.
The Wikipedia has the following information about this codepoint:
Ö, or ö, is a character that represents either a letter from several extended Latin alphabets, or the letter "o" modified with an umlaut or diaeresis. Ö, or ö, is a variant of the letter O. In many languages, the letter "ö", or the "o" modified with an umlaut, is used to denote the close- or open-mid front rounded vowels [ø] or [œ] . In languages without such vowels, the character is known as an "o with diaeresis" and denotes a syllable break, wherein its pronunciation remains an unmodified [o].