HTML: The Markup Language

2. Terminology # T

The following is a list of terms that are used in other sections of this specification.

browsing context
A browsing context is an environment in which UAs present documents to users. A tab or window in a Web browser typically contains a browsing context, as does an iframe, or frame elements in a frameset.
case-insensitive match
For the purposes of this specification, performing a case-insensitive match between two strings means comparing the strings exactly, codepoint for codepoint, except that the characters in the range A-Z and the corresponding characters in the range a-z are considered to also match.
fallback content
Some embedded content elements can have fallback content: content that is to be used when the embedded content cannot be used (for example, when it is of an unsupported format).
flow content
Flow content consists of flow elements intermixed with normal character data.
HTML producers
HTML authors (that is, people) and applications (such as editors and content management systems) that produce HTML content.
HTML consumers
HTML user agents; that is, applications (such as Web browsers) which consume HTML content.
A newline may be represented as any of the following:
  • a U+000D CARRIAGE RETURN (CR) character
  • a U+000A LINE FEED (LF) character
  • a U+000D CARRIAGE RETURN (CR) followed by a U+000A LINE FEED (LF) character
phrasing content
Phrasing content consists of phrasing elements intermixed with normal character data.
A space character is any of the following:
  • U+0020 SPACE
  • U+000A LINE FEED (LF)
  • U+000C FORM FEED (FF)
If the content model of a particular element foo is described as transparent, it means:
  • when element foo is a child of a parent element bar whose content model is allowed to contain flow elements, then the contents of element foo may also contain flow elements
  • when element foo is a child of a parent element baz whose content model restricts its child elements to only being phrasing elements, then any child elements of element foo are also restricted to only being phrasing elements