1 What is Unicode?

The Unicode is an international standard that assigns numbers to characters (symbols) for processing text and scripts with computers.

2 Entering Unicode

There are many ways how to enter Unicode characters. Depending on the operating system and program, you can enter Unicode characters by number or with a tool.

In some tools it makes a difference whether a Unicode character is in the BMP, that is the first 65536 Unicode code points, or another plane. There are three types of tools:

• Tools which accept any number from any plane without difference, such as GTK.
• Tools which accept any number from any plane, but have different shortcuts for the BMP and other planes, such as Vim.
• Tools which accept only input from the BMP, and thus need a surrogate pair to enter code points from other planes, such as IdeaVim and Mac OS.

2.1 In Vim

BMP / 16 Bit: Ctrl+V,U followed by the 4 hexadecimal digits of the Unicode code point.

Other planes / 32 Bit: Ctrl+V,Shift+U followed by the 8 hexadecimal digits of the Unicode code point.

For example: To enter the bullet character '•' in Vim, press Ctrl+V U 2 0 2 2. To enter the keyboard and mouse symbol '🖦' in Vim, press Ctrl+V Shift+U 0 0 0 1 F 5 A 6.

2.2 In IdeaVim

BMP / 16 Bit: Ctrl+V,U followed by the 4 hexadecimal digits of the Unicode code point.

Other planes / 32 Bit: IdeaVim currently does not natively support entering 32 Bit Unicode characters. The shortcut Ctrl+V,Shift+U is accepted and expects 8 hexadecimal digits, but only the last four digits have an effect. It is still possible to enter Unicode characters from the supplementary planes in IdeaVim. For that, one has to convert the code point into a surrogate pair. For example, to enter the keyboard and mouse symbol '🖦' (codepoint 0x1F5A6) in IdeaVim, type Ctrl+V U D 8 3 D Ctrl+V U D D A 6.

2.3 In GTK

All codepoints: Ctrl+Shift+U followed by the hexadecimal digits followed by space.

For example: To enter the bullet character in X11, press Ctrl+Shift+U 2 0 2 2 SPACE. To enter the keyboard and mouse symbol in X11, press Ctrl+Shift+U 1 F 5 A 6.

2.4 Plain X11 / KDE / Non-GTK

I'm afraid that plain X11, KDE and other non-GTK applications do not have good support for Unicode input.

2.5 In Windows

Some Windows applications support entering Unicode by typing the hexadecimal code point number followed by Alt+X. For example, to enter the keyboard and mouse symbol '🖦' (codepoint 0x1F5A6) in WordPad, type 1 F 5 A 6 Alt+X. Note that this doesn't work in all Windows applications. It works, for example, in Outlook, Word, and WordPad. And it doesn't work, for example, in Chrome, cmd.exe, Excel, File Explorer, or Teams.

3 List of Useful Unicode Code Points

4 Rating

One of the things you can do with plain Unicode stars is to create a rating.

<p>
    Average Rating:
    <span style="color: hsl(45, 100%, 50%);">&#x2605;&#x2605;&#x2605;&#x2606;&#x2606;</span>
</p>

This can also be used in tools like Google Sheets. For example, in a product comparison, one might want to have a column "First Impression" and use a star rating there.

Of course, you may want to go for something more complex in a proper product rating on a website. This can still be useful for stubbing and mockups.

5 Choosing between Text Mode and Emoji Mode

When entering Unicode characters that represent emojis, it is possible to control whether a normal character or an emoji shall be shown. In the Unicode, this is called Variant Selector. The code points FE0E and FE0F can be used after a character to select between text and emoji. If neither of them is present, the software is free to decide.

For example, when entering 2611 in Slack, the default behavior of Slack is to replace it with an emoji. When entering 2611 followed by FE0E, the character is selected explicitly, and Slack will no longer replace it with an emoji.

Whether software respects the choice can also be influenced by the availability of corresponding fonts, and their correctness.

6 Emoji Gender

Some emojis represent humans, humanoids, or even animals, and exist in forms with multiple genders. Some of these emojis exist via separate code points, which the specification calls explicit gender appearance. For others, it is possible to select the gender by marking the gender using a zero width joiner 200D with an explicit gender marker. The gender markers are based on the astronomical symbols for the planets Venus (female) and Mars (male).

The Emoji mode variant selector is important. Without it, some applications might not display the modified emoji, but instead display the gender symbol separately.

7 Emoji Diversity

Emojis which represent humans or human body parts like hands or heads often have a skin color. To represent diversity, emojis can be modified with a skin tone modifier. The skin tone modifier is based on the Fitzpatrick Scale, with the skin types I and II on the Fitzpatrick scale clubbed together.

Together with the option of not specifying the skin type, this gives a total of 6 options for specifying the skin type. The skin type modifier is simply used after the emoji of which the skin type is to be modified.

8 Combining Gender and Diversity

Of course the modifiers for gender and diversity can be combined.

9 Emoji Flags

9.1 Country Flags

Country flags are a bit special in the Unicode, in multiple ways. First, Unicode doesn't specify flags as such, just a mechanism how to specify flags. Second, flags need two code points instead of one.

Flags are represented by two flag letters. The combination of the two flag letters represents the ISO 3166-1 alpha-2 two-letter country code.

For example, the two-letter country code for Germany is DE. So, the flag for Germany is represented by 🇩 (1F1E9) followed by 🇪 (1F1EA): 🇩🇪 (1F1E9 1F1EA).

9.2 Region Flags

Regional flags work different from country flags, and they are mostly unsupported (yet?). Regional flags work by taking the black flag 🏴 (1F3F4) and tagging it with the region, without the dash, and all lowercase. The tag sequence must be correctly closed (canceled with E007F cancel tag). The tags for that are in Unicode code page [UnicodeE0000].

9.3 Combined Flags

It is also possible to create flags by combining the white or black flag with the symbol of choice using the zero-width joiner 200D. This is not very widely supported, except for the pirate flag and the rainbow flag.

10 Browsers

As noted in the info box at the beginning of this article, the correct display depends on a couple of things. Most notably, it depends on the presence of emoji-fonts and how up-to-date these fonts are.

• On some flavors of Ubuntu, like for example Kubuntu, the package fonts-noto-color-emoji has to be installed to get emoji support in some browsers and other software.