Reserved characters in HTML must be replaced with character entities.
HTML Entities
Some characters are reserved in HTML.
If you use the less than (<) or greater than (>) signs in your text, the browser might mix them with tags.
Character entities are used to display reserved characters in HTML.
A character entity looks like this:
&entity_name;
OR
&#entity_number;
To display a less than sign (<) we must write: < or <
Advantage of using an entity name: An entity name is easy to remember.
Disadvantage of using an entity name: Browsers may not support all entity names, but the support for entity numbers is good.
Non-breaking Space
A commonly used entity in HTML is the non-breaking space:
A non-breaking space is a space that will not break into a new line.
Two words separated by a non-breaking space will stick together (not break into a new line). This is handy when breaking the words might be disruptive.
Examples:
§ 10
10 km/h
10 PM
Another common use of the non-breaking space is to prevent browsers from truncating spaces in HTML pages.
If you write 10 spaces in your text, the browser will remove 9 of them. To add real spaces to your text, you can use the character entity.
Tip: The non-breaking hyphen (‑) is used to define a hyphen character (‑) that does not break into a new line.
Some Useful HTML Character Entities
Result Description Entity Name Entity Number
non-breaking space  
< less than < <
> greater than > >
& ampersand & &
" double quotation mark " "
' single quotation mark (apostrophe) ' '
¢ cent ¢ ¢
£ pound £ £
¥ yen ¥ ¥
€ euro € €
© copyright © ©
® registered trademark ® ®
Combining Diacritical Marks
A diacritical mark is a "glyph" added to a letter.
Some diacritical marks, like grave ( ̀) and acute ( ́) are called accents.
Diacritical marks can appear both above and below a letter, inside a letter, and between two letters.
Diacritical marks can be used in combination with alphanumeric characters to produce a character that is not present in the character set (encoding) used in the page.
Here are some examples:
Mark Character Construct Result
̀ a à à
́ a á á
̂ a â â
̃ a ã ã
̀ O Ò Ò
́ O Ó Ó
̂ O Ô Ô
̃ O Õ Õ
You will see more HTML symbols in the next chapter of this tutorial.