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 acts as Other Neutral. When changing direction it is not mirrored. The word that U+213A forms with similar adjacent characters prevents a line break inside it.
The Wikipedia has the following information about this codepoint:
A signature mark, in traditional bookbinding, is a letter, number or combination of either or both, which is printed at the bottom of the first page, or leaf, of a section.
The section is itself referred to as a signature, also called collation or gathering.
The aim is to ensure that the binder can order the pages and sections in the correct order. Often the letters of the Latin alphabet were used.
The practice has been superseded by advances in printing and bookbinding technology. As a result, signature marks are rarely found in modern books.
Representations
System
Representation (click value to copy)
Nº
8506
UTF-8
E2 84 BA
UTF-16
21 3A
UTF-32
00 00 21 3A
URL-Quoted
%E2%84%BA
HTML hex reference
℺
Wrong windows-1252 Mojibake
℺
Encoding: GB18030 (hex bytes)
81 36 C0 38
RFC 5137
\u'213A'
Bash and Zsh inside echo -e
\u213A
C and C++
\u213A
C#
\u213A
CSS
\00213A
Excel
=UNICHAR(8506)
Go
\u213A
JavaScript
\u213A
Modern JavaScript since ES6
\u{213a}
JSON
\u213A
Java
\u213A
Lua
\u{213A}
Matlab
char(8506)
Perl
"\x{213A}"
PHP
\u{213a}
PostgreSQL
U&'\213A'
PowerShell
`u{213A}
Python
\u213A
Ruby
\u{213a}
Rust
\u{213a}
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