This character is a Other Punctuation and is commonly used, that is, in no specific script.
The glyph is a small version of the glyph Glyph for U+003AColon. Its East Asian Width is wide. In bidirectional text it is written as number separator according to the number it separates. When changing direction it is not mirrored. It will not end a sentence. U+FE55 prohibits line breaks before its position. There might be some exceptions, though.
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
65109
UTF-8
EF B9 95
UTF-16
FE 55
UTF-32
00 00 FE 55
URL-Quoted
%EF%B9%95
HTML hex reference
﹕
Wrong windows-1252 Mojibake
﹕
Encoding: BIG5 (hex bytes)
A1 52
Encoding: BIG5HKSCS (hex bytes)
A1 52
Encoding: CP950 (hex bytes)
A1 52
Encoding: GBK (hex bytes)
A9 73
Encoding: GB18030 (hex bytes)
A9 73
Adobe Glyph List
colonsmall
RFC 5137
\u'FE55'
Bash and Zsh inside echo -e
\uFE55
C and C++
\uFE55
C#
\uFE55
CSS
\00FE55
Excel
=UNICHAR(65109)
Go
\uFE55
JavaScript
\uFE55
Modern JavaScript since ES6
\u{fe55}
JSON
\uFE55
Java
\uFE55
Lua
\u{FE55}
Matlab
char(65109)
Perl
"\x{FE55}"
PHP
\u{fe55}
PostgreSQL
U&'\FE55'
PowerShell
`u{FE55}
Python
\uFE55
Ruby
\u{fe55}
Rust
\u{fe55}
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.)