The glyph is a canonical composition of the glyphs Glyph for U+0055Latin Capital Letter U, Glyph for U+031BCombining Horn. 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+01AF forms with similar adjacent characters prevents a line break inside it.
The Wikipedia has the following information about this codepoint:
Ư (lowercase ư) is one of the 12 Vietnamese language vowels. It is pronounced [ɨ] or [ɯ].
As with most special Vietnamese letters, this letter is not well-supported by fonts and is often typed as either u+ or u*. The VIQR standard is u+.
Because Vietnamese is a tonal language this letter may optionally have any one of the 5 tonal symbols above or below it.