| Character | Notation | Render |
|---|---|---|
| a1 word space |   | | | |
| a2 no-break space |   | | | |
| en space |   | | | |
| en quad |   | | | |
| em quad |   | | | |
| em space |   | | | |
| a6 three-per-em |   | | | |
| a7 four-per-em |   | | | |
| a7 six-per-em |   | | | |
| figure space |   | | | |
| a2 Punctuation space |   | | | |
| a4 thin space |   | | | |
| a5 hair space |   | | | |
Two useful spaces in the HTML repertoire are the en space   and the em space  .
Both are visibly wider than a normal space, as mandated in the official HTML specification.
| Character | Code | Render |
|---|---|---|
| zero width space | ​ | || |
| zero width non-joiner | ‌ | || |
| zero width joiner | ‍ | || |
| zero width no-break space |  | || |
| left-to-right mark | ‎ | || |
| right-to-left mark | ‏ | || |
| line separator | 
 | | | |
| paragraph separator | 
 | | | |
| left-to-right embedding | ‪ | || |
| right-to-left embedding | ‫ | || |
| formatting | ‬ | || |
| left-to-right override | ‭ | || |
| right-to-left override | ‮ | || |
| left-to-right mark | ‎ | || |
| right-to-left mark | ‏ | || |
Sometimes in typesetting you need to provide a hint that the computer can break a long word in a particular position without any other interpretation or visible indication.
This is the zero width space : ​
Its twin is the zero width no-break space :  which can be used to keep a word from breaking at that point.