HTML 提供了一些显示保留字符的方法。保留字符是为 HTML 保留的字符或基本键盘中不存在的字符。
例如： ‘<‘ 在 HTML 语言中已经被保留。有时这个字符需要显示在网页上，这会在代码中造成歧义。除了这些字符，基本键盘中通常不存在的字符（£、¥、€、©）等。
HTML 提供了一些实体名称和实体编号以使用此符号。实体编号简单易学。一些有用的符号及其实体名称和实体编号如下。
| Notation | Symbols | Entity name | Entity Number |
|---|---|---|---|
| non-breaking space | |||
| < | less than | < | < |
| ® | registered trademark | ® | ® |
| © | copyright | © | © |
| € | euro | € | € |
| ¥ | yen | ¥ | ¥ |
| £ | pound | £ | £ |
| ¢ | cent | ¢ | ¢ |
| “ | double quotation mark | " | " |
| & | ampersand | & | & |
| > | greater than | > | > |
| ∂ | PARTIAL DIFFERENTIAL | ∂ | ∂< |
| ∃ | THERE EXISTS | ∃ | ∃ |
| ∅ | EMPTY SETS | ∅ | ∅ |
| ∇ | NABLA | ∇ | ∇ |
| ∈ | ELEMENT OF | ∈ | ∈ |
| ∉ | NOT AN ELEMENT OF | ∉ | ∉ |
| ∋ | CONTAINS AS MEMBER | ∋ | 8715 |
| ∏ | N-ARY PRODUCT | ∏ | ∏ |
| ∑ | N-ARY SUMMATION | ∑ | ∑ |
| Α | Alpha | Α | Α |
| Β | Beta | Β | Β |
| Γ | Gamma | Γ | Γ |
| Δ | delta | Δ | Δ |
| Ε | Epsilon | Ε | Ε |
| Ζ | Zeta | Ζ | Ζ |
| ♥ | BLACK HEART SUIT | ♥ | ♥ |
| ♣ | BLACK CLUB SUIT | ♣ | ♣ |
| ♠ | BLACK SPADE SUIT | ♠ | ♠ |
| ↓ | DOWNWARDS ARROW | ↓ | ↓ |
| → | RIGHTWARDS ARROW | → | → |
| ↑ | UPWARDS ARROW | ↑ | ↑ |
| ← | LEFTWARDS ARROW | ← | ← |
| ™ | TRADEMARK | ™ | ™ |
| ♦ | BLACK DIAMOND SUIT | ♦ | ♦ |
| ° | degree | ° | ° |
| ∞ | infinity | ∞ | ∞ |
| ‰ | per-mille | ‰ | ‰ |
| ⋅ | multiplication dot | ⋅ | ⋅ |
| ± | plus-minus | ± | ± |
| † | hermitian | † | † |
| — | – | — | — |
| ¬ | – | ¬ | ¬ |
| µ | Micro (mu) | µ | µ |
| ⊥ | falsum | ⊥ | ⊥ |
| ∥ | parallel | ∥ | ∥ |
例子：
html
HTML Entities
Showing euro €
Showing cent ¢
Showing Copyright ©
Showing BLACK DIAMOND SUIT ♦
Showing TRADEMARK ™
输出
支持的浏览器：
- 谷歌浏览器
- 微软边缘
- 火狐
- 歌剧
- 苹果浏览器