Unicode

I need help with this – Marty McFly

Also, to the OP, you shouldn't really write a "How To" on Unicode

About

Unicode is the modern standard for working with text on computers. Unicode is a very large set of standards

Super combined characters

Unicode includes characters that instead of acting like characters of their own add marks to other characters. This is intended for representing characters such as the Spanish ñ (even if the most common ones have dedicated values). However, some users have found that it is possible to stack lots of combining characters on top of a single base character.

Control codes

Unicode, like other character sets, include some control codes. They perform a special task instead of printing a character. The most basic example is the newline, but many others exist.

RTL/LTR overrides

Unicode allows the text to override the text direction, allowing for easy inclusion of text in the wrong direction. This can be used for griefing if the text direction is not correctly managed and included in a larger system such as a chat.

Nospace joiner and friends

Some of the control codes do absolutely nothing except technically counting as a character. They don't print anything and they don't consume any space visually. This can be abused to fool word filters and similar.

Upside down text

Unicode includes so many characters that people have been able to find characters that look similar enough to upside down versions of basic Latin characters.

Dingbats

Unicode includes many characters that are pictographical, they use a picture to represent a concept. Advanced emoticons take advantage of the rich character set.

Precursors

Special symbol fonts such as Wingdings and Marlett has previously been used to show text as symbols.

Visually identical characters

Unicode includes many characters that can easily be confused with each other, some even looking exactly identical in many fonts. This can be abused to cause confusion.^[2]

External References