2.01. Terms used in other parts of the specification # T

The following is a list of terms that are common to various other sections in this specification.

browsing context

A browsing context is a collection of one or more documents and one or more views.

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).

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

newline

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

space

A space character is any of the following:

• U+0020 SPACE
• U+0009 CHARACTER TABULATION (tab)
• U+000A LINE FEED (LF)
• U+000C FORM FEED (FF)
• U+000D CARRIAGE RETURN (CR)

view

A view is as defined in Document Object Model (DOM) Level 2 Views [DOM2VIEWS].

2.02. Symbols used in content models # T

This section provides explanations for the symbols used in the Content model and Attribute model subsections of the per-element documentation in the HTML elements section and in the Common content models, Common attributes, and Forms attributes sections.

The explanations use the term group to mean any combination of names and symbols that are delimited by a pair of matching "(" and ")" (parentheses) symbols, and the term pattern name to mean any hyperlinked name used in a definition that is not an element name or an attribute name.

? (optional)

The "?" (question mark) symbol after an element name, attribute name, pattern name, or group indicates that it is optional — meaning that it can either not occur at all, or it can occur exactly once.

* (zero or more)

The "*" (asterisk) symbol after an element name, pattern name, or group indicates that it may occur any number of times, including not occurring at all.

+ (one or more)

The "+" (plus sign) symbol after an element name, pattern name, or group indicates that is must occur at least once, and can occur more than once.

| (either/or choice)

The "|" (vertical line) symbol between element names, attribute names, pattern names, and groups indicates an either/or alternative relationship between the two items it separates; that is, it indicates that either the item before the "|" symbol can occur, or the item after the symbol can occur.

, (in the order shown)

The "," (comma) symbol between element names, pattern names, and groups indicates that the two items it separates can only occur in the order shown.

& (interleaved in any order)

The "&" (ampersand) symbol between element names, attribute names, pattern names, and groups indicates that the two items it separates can occur in any order.