This character is a Other Punctuation and is mainly used in the Syriac script.
The glyph is not a composition. It has no designated width in East Asian texts. In bidirectional text it is written as Arabic letter from right to left. When changing direction it is not mirrored. The word that U+0703 forms with similar adjacent characters prevents a line break inside it. The glyph can be confused with one other glyph.
The Wikipedia has the following information about this codepoint:
The colon, :, is a punctuation mark consisting of two equally sized dots aligned vertically. A colon often precedes an explanation, a list, or a quoted sentence. It is also used between hours and minutes in time, between certain elements in medical journal citations, between chapter and verse in Bible citations, and, in the US, for salutations in business letters and other formal letter writing.
Representations
System
Representation (click value to copy)
Nº
1795
UTF-8
DC 83
UTF-16
07 03
UTF-32
00 00 07 03
URL-Quoted
%DC%83
HTML hex reference
܃
Wrong windows-1252 Mojibake
܃
Encoding: GB18030 (hex bytes)
81 31 99 39
RFC 5137
\u'0703'
Bash and Zsh inside echo -e
\u0703
C and C++
\u0703
C#
\u0703
CSS
\000703
Excel
=UNICHAR(1795)
Go
\u0703
JavaScript
\u0703
Modern JavaScript since ES6
\u{703}
JSON
\u0703
Java
\u0703
Lua
\u{703}
Matlab
char(1795)
Perl
"\x{703}"
PHP
\u{703}
PostgreSQL
U&'\0703'
PowerShell
`u{703}
Python
\u0703
Ruby
\u{703}
Rust
\u{703}
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.)