This character is a Math 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 acts as Other Neutral. When changing direction it is not mirrored. The word that U+25F9 forms with similar adjacent characters prevents a line break inside it.
The Wikipedia has the following information about this codepoint:
Geometric Shapes is a Unicode block of 96 symbols at code point range U+25A0–25FF.
Representations
System
Representation (click value to copy)
Nº
9721
UTF-8
E2 97 B9
UTF-16
25 F9
UTF-32
00 00 25 F9
URL-Quoted
%E2%97%B9
HTML hex reference
◹
Wrong windows-1252 Mojibake
â—¹
HTML named entity
◹
Encoding: GB18030 (hex bytes)
81 37 A2 30
RFC 5137
\u'25F9'
Bash and Zsh inside echo -e
\u25F9
C and C++
\u25F9
C#
\u25F9
CSS
\0025F9
Excel
=UNICHAR(9721)
Go
\u25F9
JavaScript
\u25F9
Modern JavaScript since ES6
\u{25f9}
JSON
\u25F9
Java
\u25F9
Lua
\u{25F9}
Matlab
char(9721)
Perl
"\x{25F9}"
PHP
\u{25f9}
PostgreSQL
U&'\25F9'
PowerShell
`u{25F9}
Python
\u25F9
Ruby
\u{25f9}
Rust
\u{25f9}
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