This character is a Nonspacing Mark and is mainly used in the Hebrew script. The character is also known as tsinorit, zinorit; tsinor and zinor.
The glyph is not a composition. It has no designated width in East Asian texts. In bidirectional text it acts as Nonspacing Mark. When changing direction it is not mirrored. U+0598 prohibits a line break before it. The glyph can be confused with one other glyph.
The Wikipedia has the following information about this codepoint:
Tsinnorit (Hebrew צִנּוֹרִת֘) is a cantillation mark in the Hebrew Bible, found at the 3 poetic books, also known as the Sifrei Emet books (Emet is an acronym of hebrew titles from three books, Job or אִיוֹב in Hebrew, Proverbs or מִשְלֵי, and Psalms or תְהִלִּים). It looks like a 90-degrees rotated, inverted S, placed on top of a Hebrew consonant. Tsinnorit is very similar in shape to Zarka (called tsinnor in the poetic books), but is used differently. It is always combined with a second mark to form a conjunctive symbol:
Tsinnorit combines with (merkha to form merkha metsunneret, a rare variant of merkha that serves mainly sof pasuq.
Tsinnorit combines with mahapakh to form mehuppakh metsunnar, also a rare mark, variant of mahapakh that serves mainly azla legarmeh but appears also in the other contexts where mahapakh and illuy appear.
This mark has been wrongly named by Unicode. Zarqa/tsinnor corresponds to Unicode "Hebrew accent zinor", code point U+05AE (where "zinor" is a misspelled form for tsinnor), while tsinnorit maps to "Hebrew accent zarqa", code point U+0598.