prefix CSS at-rule descriptor

Syntax

/* <symbol> value: string, image, or identifier */
prefix: "»";
prefix: "Page ";
prefix: url("bullet.png");

Values

The prefix descriptor takes as its value a single <symbol>:

<symbol>

Specifies a <symbol> — a <string>, <image>, or <custom-ident> — that is prepended to the marker representation.

Formal definition

Formal syntax

prefix = 
  <symbol>  

<symbol> = 
  <string>        |
  <image>         |
  <custom-ident>  

<image> = 
  <url>           |
  <image()>       |
  <image-set()>   |
  <cross-fade()>  |
  <element()>     |
  <gradient>      

<image()> = 
  image( <image-tags>? [ <image-src>? , <color>? ]! )  

<image-set()> = 
  image-set( <image-set-option># )  

<cross-fade()> = 
  cross-fade( <cf-image># )  

<element()> = 
  element( <id-selector> )  

<image-tags> = 
  ltr  |
  rtl  

<image-src> = 
  <url>     |
  <string>  

<image-set-option> = 
  [ <image> | <string> ] [ <resolution> || type( <string> ) ]?  

<cf-image> = 
  [ <image> | <color> ]  &&
  <percentage [0,100]>?  

<id-selector> = 
  <hash-token>  

Examples

Adding a prefix to a counter

In this example, each counter number is prefixed by "Book " (with a space) and followed by a colon (:). The colon is added with the suffix descriptor.

HTML

<ol class="books">
  <li>Flamer, by Mike Curato</li>
  <li>Gender Queer: A Memoir, by Maia Kobabe</li>
  <li>Tricks, by Ellen Hopkins</li>
  <li>The Handmaid's Tale: The Graphic Novel, by Margaret Atwood</li>
  <li>Crank, by Ellen Hopkins</li>
</ol>

CSS

@counter-style books {
  system: numeric;
  symbols: "0" "1" "2" "3" "4" "5" "6" "7" "8" "9";
  prefix: "Book ";
  suffix: ": ";
}

.books {
  list-style: books;
  padding-left: 15ch;
}

Result

Specifications

Browser compatibility

See also

• Other @counter-style descriptors: system, symbols, additive-symbols, negative, suffix, range, pad, speak-as, and fallback
• list-style, list-style-image, list-style-position
• symbols(): the functional notation for creating anonymous counter styles
• CSS counter styles module
• CSS lists and counters module