Datatypes
- Absolute URI
- Browsing-context name
- Browsing-context name or keyword
- Character encoding name
- Character-encoding name list
- Circle
- Color
- Date
- Date-time
- Date or time
- Default-style name
- E-mail address
- E-mail address list
- Float
- Hash-name reference
- ID
- IDREF
- IDREFS
- ifrmae srcdoc
- Integer
- Key-label list
- Language tag
- Local date-time
- Media-query list
- Meta-charset string
- MIME type
- MIME-type list
- Month
- Name
- Non-negative float
- Non-negative integer
- Pattern
- Polygon
- Positive float
- Positive integer
- Rectangle
- Refresh value
- Sandbox allow list
- Sizes
- String
- Time
- Token
- Tokens
- URI
- Week
- Zero
Absolute URI
An IRI, as defined in RFC 3987.
/hello #canvas http://example.org/
Browsing-context name
Any string, with the following restrictions:
- must not start with a "_" character
- must be at least one character long
Browsing-context name or keyword
Any string that is either of the following:
- a browsing-context name
- any case-insensitive match for one of the following literal strings:
- _blank
- _parent
- _self
- _top
Character encoding name
For documents in the HTML syntax: a case-insensitive match for any character set name given in a Name or Alias field labeled as "preferred MIME name" in the IANA Character Sets registry [IANACHARSET], if there is one; or if none of the Alias fields are so labeled, a case-insensitive match for a Name field in the registry.
For documents in the XML syntax, any case-insensitive match for the string "UTF-8".
Character-encoding name list
A set of comma-separated tokens, each of which is a valid character encoding name that specifies an ASCII-compatible character encoding.
Circle
A comma-separated list of three numbers, in exactly the following order:
- an integer representing the distance in CSS pixels from the left edge of the image to the center of the circle
- an integer representing the distance in CSS pixels from the top edge of the image to the center of the circle
- a non-negative integer, representing the radius of the circle, in CSS pixels
Color
A string exactly seven characters long, consisting of the following parts, in exactly the following order:
- A "#" character
- Six characters in the range 0-9, a-f, and A-F
Date
A valid full-date, as defined in RFC 3339, with the additional qualification that the year component is a date-fullyear as defined in this document.
1996-12-19
Date-time
A valid date-time, as defined in RFC 3339, with these additional qualifications:
- the literal letters T and Z in the date/time syntax must always be uppercase
- a date-fullyear is defined as four or more digits representing a number greater than 0
1990-12-31T23:59:60Z 1996-12-19T16:39:57-08:00
Date or time
Any one of the following:
- date
- time
- datetime
Default-style name
A string.
E-mail address
Any string that matches the following ABNF production:
1*( atext / "." ) "@" ldh-str 1*( "." ldh-str )
...where atext is as defined in RFC 5322, and ldh-str is as defined in RFC 1034.
e-mail.address@example.com
E-mail address list
A set of comma-separated tokens, each of which is a valid email address.
Float
A float consists of the following parts, in exactly the following order:
- Optionally, the first character may be a "-" character
- One or more characters in the range "0-9"
- Optionally, the following parts, in exactly the following order:
- A "." character
- One or more characters in the range "0-9"
- Optionally, the following parts, in exactly the following order:
- A "e" character or "E" character
- Optionally, a "-" character or "+" character
- One or more characters in the range "0-9"
Hash-name reference
A valid hash-name reference to an element of type type is a string that starts with a "#" character, followed by a string which exactly matches the value of the name attribute of an element in the document with type type.
ID
Any string, with the following restrictions:
- must be at least one character long
- must not contain any space characters
- Note: Previous versions of HTML placed greater restrictions on the content of ID values (for example, they did not permit ID values to begin with a number)
IDREF
Any string, with the following restrictions:
- must be at least one character long
- must not contain any space characters
IDREFS
A space-separated list of one or more IDREF instances.
iframe srcdoc
The content of the page that the nested browsing context is to contain.
Integer
One or more characters in the range 0-9, optionally prefixed with a "-" character.
Key-label list
An ordered set of unique space-separated tokens, each of which must be exactly one Unicode code point in length.
Language tag
A valid language tag, as defined in RFC 5646.
Local date-time
The following parts, in exactly the following order:
- A date
- The literal string "T"
- A time
1985-04-12T23:20:50.52 1996-12-19T16:39:57
Media-query list
A valid media query list, as defined in Media Queries.
Meta-charset string
The following parts, in exactly the following order:
- The literal string "text/html;"
- Optionally, one or more space characters
- The literal string "charset="
- A character encoding name
MIME type
A string that identifies a valid MIME media type, as defined in RFC 2046.
MIME-type list
A set of comma-separated tokens, each of which is a valid mime type, with no parameters.
Month
The following parts, in exactly the following order:
- A date-fullyear
- The literal string "-"
- A date-month, as defined in RFC 3339
1996-12
Name
Any string, with the following restrictions:
- must be at least one character long
- must not contain any space characters
Non-negative float
A float, with the following restriction:
- the first character may not be a "-" character
Non-negative integer
One or more characters in the range 0-9.
Pattern
A regular expression that must match the JavaScript Pattern production ECMA262.
Polygon
A comma-separated list of at least six integers, with the total number of integers in the list being even (that is, six or eight or ten numbers, and so on). Each pair of integers represents a coordinate, in CSS pixels, given as the distances from, respectively, the left and the top of the image; all the coordinates together represent the points of the polygon, in order.
Positive float
A non-negative float, with the following restriction:
- must be greater than zero
Positive integer
Any non-negative integer, with the following restriction:
- must be greater than zero
Rectangle
A comma-separated list of four integers, in exactly the following order:
- an integer representing the distance in CSS pixels from the left edge of the image to the left side of the rectangle
- an integer representing the distance in CSS pixels from the top edge of the image to the top side of the rectangle
- an integer, greater than the value of the first integer in this list, representing the distance in CSS pixels from the left edge of the image to the right side of the rectangle
- an integer, greater than the value of the second integer in this list, representing the distance in CSS pixels from the top edge of the image to the bottom side of the rectangle
Refresh value
Any one of the following:
- A non-negative integer.
- The string consisting of the following parts, in exactly the following order:
- A non-negative integer
- A ";" character
- One or more space characters
- A case-insensitive match for the string "url="
- A URI
Sandbox allow list
An unordered set of unique space-separated tokens, each of which is a case-insensitive match for one of the following literal strings:
- "allow-same-origin"
- "allow-forms"
- "allow-scripts"
- "allow-top-navigation"
Sizes
An unordered set of unique space-separated tokens, each of which must be one of the following:
- the literal string "any"
- two valid non-negative integers that do not have a leading "0" character and that are separated by a single "x" character
String
For any attribute definition in this document that references the string datatype, a string is defined as normal character data.
The Attributes section of this document describes additional restrictions on strings in attribute values - in particular, restrictions for the following cases:
- unquoted attribute values
- single-quoted attribute values
- double-quoted attribute values
Time
A valid partial-time, as defined in RFC 3339.
23:20:50.52 17:39:57
Token
For any attribute definition in this document that references the token datatype, a token is defined as a string that does not contain any space characters.
Tokens
A space-separated list of zero or more token instances.
URI
An IRI-reference, as defined in RFC 3987.
Note: The empty string is a valid IRI-reference, so the empty string is allowed as the value of any attribute for which this document defines URI as the allowed datatype.
http://example.org/hello
Week
The following parts, in exactly the following order:
- A date-fullyear
- The literal string "-W"
- A date-week, as defined in RFC 3339
1996-W16
Zero
The literal string "0".