This character is a Other Symbol and is commonly used, that is, in no specific script.
The glyph is not a composition. 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+1D10A forms with similar adjacent characters prevents a line break inside it.
The Wikipedia has the following information about this codepoint:
Da capo ( dah KAH-poh, US also dΙ -β , Italian:[da(k)ΛkaΛpo]; often abbreviated as D.C.) is an Italian musical term that means "from the beginning" (literally, "from the head"). The term is a directive to repeat the previous part of music, often used to save space, and thus is an easier way of saying to repeat the music from the beginning.
In small pieces, this might be the same thing as a repeat. But in larger works, D.C. might occur after one or more repeats of small sections, indicating a return to the very beginning. The resulting structure of the piece is generally in ternary form. Sometimes, the composer describes the part to be repeated, for example: Menuet da capo. In opera, where an aria of this structure is called a da capo aria, the repeated section is often adorned with grace notes.
The word Fine (Ital. 'end') is generally placed above the stave at the point where the movement ceases after a 'Da capo' repetition. Its place is occasionally taken by a pause (see fermata)."