This character is a Other Punctuation 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. It can end sentences at appropriate places. U+203D prohibits line breaks before its position. There might be some exceptions, though.
The CLDR project calls this character “interrobang” for use in screen reading software. It assigns these additional labels, e.g. for search in emoji pickers: interabang.
The Wikipedia has the following information about this codepoint:
The interrobang (), also known as the interabang‽ (often represented by any of the following: ?!, !?, ?!?,?!!, !?? or !?!), is an unconventional punctuation mark intended to combine the functions of the question mark (also known as the interrogative point) and the exclamation mark (also known in the jargon of printers and programmers as a "bang"). The glyph is a ligature of these two marks and was first proposed in 1962 by Martin K. Speckter.
Representations
System
Representation (click value to copy)
Nº
8253
UTF-8
E2 80 BD
UTF-16
20 3D
UTF-32
00 00 20 3D
URL-Quoted
%E2%80%BD
HTML hex reference
‽
Wrong windows-1252 Mojibake
‽
Encoding: GB18030 (hex bytes)
81 36 A8 31
RFC 5137
\u'203D'
Bash and Zsh inside echo -e
\u203D
C and C++
\u203D
C#
\u203D
CSS
\00203D
Excel
=UNICHAR(8253)
Go
\u203D
JavaScript
\u203D
Modern JavaScript since ES6
\u{203d}
JSON
\u203D
Java
\u203D
Lua
\u{203D}
Matlab
char(8253)
Perl
"\x{203D}"
PHP
\u{203d}
PostgreSQL
U&'\203D'
PowerShell
`u{203D}
Python
\u203D
Ruby
\u{203d}
Rust
\u{203d}
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