This is a visibly displayed graphic character (used in left-to-right symbolic notations), not an invisible composition control. It is used with other characters from the Ideographic Description Characters block, and two special CJK indicators U+303E and U+303F in the CJK Symbols and Punctuation block.
Note that this ideographic description character U+31EF at end of this block was added in Unicode 15.1, and may not be rendered correctly unless some updated font is installed on your system. It should display a dashed minus sign in a dashed square box (not an X cross in a rectangular box, which would make it confusable with the special CJK indicator U+303F).
Subcategories
This category has the following 4 subcategories, out of 4 total.