This character is a Other Letter and is mainly used in the Bopomofo script.
The glyph is not a composition. Its East Asian Width is wide. In bidirectional text it is written from left to right. When changing direction it is not mirrored. U+3124 offers a line break opportunity at its position, except in some numeric contexts.
The Wikipedia has the following information about this codepoint:
Bopomofo, also called Zhuyin Fuhao (注音符號; Zhùyīn fúhào; 'phonetic symbols'), or simply Zhuyin, is a transliteration system for Standard Chinese and other Sinitic languages. It is commonly used in Taiwan. It consists of 37 characters and five tone marks, which together can transcribe all possible sounds in Mandarin Chinese.
Bopomofo was first introduced in China during the 1910s by the Beiyang government, where it was used alongside Wade–Giles, a romanization system which used a modified Latin alphabet. Today, Bopomofo is more common in Taiwan than on the mainland, and is used as a secondary electronic input method for Taiwanese Mandarin, as well as in dictionaries and other non-official documents.
Representations
System
Representation (click value to copy)
Nº
12580
UTF-8
E3 84 A4
UTF-16
31 24
UTF-32
00 00 31 24
URL-Quoted
%E3%84%A4
HTML hex reference
ㄤ
Wrong windows-1252 Mojibake
ㄤ
Encoding: BIG5 (hex bytes)
A3 B5
Encoding: BIG5HKSCS (hex bytes)
A3 B5
Encoding: CP950 (hex bytes)
A3 B5
Encoding: GB2312 (hex bytes)
A8 E4
Encoding: GBK (hex bytes)
A8 E4
Encoding: GB18030 (hex bytes)
A8 E4
Encoding: HZ (hex bytes)
7E 7B 28 64 7E 7D
Encoding: ISO2022_JP_2 (hex bytes)
1B 24 28 41 28 64 1B 28 42
Adobe Glyph List
angbopomofo
digraph
aN
RFC 5137
\u'3124'
Bash and Zsh inside echo -e
\u3124
C and C++
\u3124
C#
\u3124
CSS
\003124
Excel
=UNICHAR(12580)
Go
\u3124
JavaScript
\u3124
Modern JavaScript since ES6
\u{3124}
JSON
\u3124
Java
\u3124
Lua
\u{3124}
Matlab
char(12580)
Perl
"\x{3124}"
PHP
\u{3124}
PostgreSQL
U&'\3124'
PowerShell
`u{3124}
Python
\u3124
Ruby
\u{3124}
Rust
\u{3124}
Click the star button next to each label to set this representation as favorite or remove it from the favorites. Favorites will be shown initially. (Favorites are stored locally on your computer and never sent over the internet.)