List of colored icons for email subject lines?

Factual Questions
1

Hi in my hotmail junk mail folder I’ve got a couple emails that have colored icons in the subject line… e.g. yellow light bulbs, red hearts with a grey arrow in them, green money bag icons, Jewish stars, etc.
The heart icon is:
=?utf-8?q?=f0=9f=92=98?=

I sent an email to myself with that in the subject line and it showed up as a heart…

Is there a list of those codes for icons somewhere?

Thanks!

2

The underlying symbols are represented by Unicode, the defacto standard these days for computer system character encoding. You can easily find Unicode charts on the Internet, although you will usually need to look for a specific character subset. The Unicode Consortium is a good starting resource. Your heart, for example, can be found here (warning, PDF), along with many others in the genre you mention (1F498 – “HEART WITH ARROW”).

The Unicode characters are usually encoded for email (and other applications, like HTTP) with UTF-8, which is used for transmission and compatibility with existing characters sets (i.e. ASCII). The (hexadecimal) UTF-8 encoding for your heart is F0 9F 92 98, which is easily discernible from your subject line. The wiki page does a good job of explaining how it works, if you are interested or are suffering from insomnia.

3

Thanks though I’m not sure how the PDF code (1F498) is related to the code I used (F0 9F 92 98) except for the last 2 digits…

4

Ha! I suppose I could’ve posted something actually useful in helping you use these symbols.

You can convert from Unicode code points to UTF-8 using a converter or a chart (your heart here) easily enough, but you don’t need to in order to use them for email and such as you’ll typically use the Unicode character code directly. How this is done depends on your OS; this article explains the process for Windows (for example: 1F498 ALT+X). For other systems, you can search for “unicode input linux” or similar depending on your particular setup. Note that the system must support the underlying Unicode character set to render the symbols correctly.

5

Also worth noting that some fonts don’t contain every Unicode character, especially those symbol characters. (The most commonly-used fonts have almost 100% coverage though.)

If you give a Unicode character to a font that doesn’t contain it, you’ll just see either a diamond with a question mark inside it, or a empty rectangle, (or possibly something else) depending on your OS.