HTML attributes

created by in10se

(idea) by in10se (4 s) (print) ? 1 C! I like it! Tue Jul 01 2003 at 18:34:59

See also: HTML tags

Note to readers: This document attempts to define all HTML attributes - not just those available for use on E2.
Please do not confuse this document with E2 HTML tags, E2 HTML, E2 HTML tags : Quick Start, or E2 FAQ: HTML.

I know this is a very long writeup, but it's a lot of information. I honestly don't expect anyone to read the whole thing, but feel free to use it as a reference. I have grouped the text into three separate sections, so in case you just want to skip to a section, look for the big headings. The sections are:

Attribute Categories
Default Values
Attribute Names

Attribute Categories

Just as HTML tags can be broken down into categories, the HTML attributes used in these tags can also be categorized. Attribute categories define the types of values that can be assigned to different attributes. All categories below specify related attributes in this group, and when applicable I have added "Valid Values" or "Common Values". "Valid Values" specify the only acceptalbe values for a group. While "Common Values" only specify values that are most often seen - other values may be acceptable.

Alignments: Alignments specify how to align one element or object with respect to another element or object
CDATA: CDATA can include any character defined by the document's character set, and may also include character entities
Related Attributes: alt, archive, axis, class, code, content, face, language, name, object, scheme, size, value, version
Character: A character as defined by ISO 10646 (i.e., a Unicode character)
Related Attributes: accesskey, char
Charset: A character set as defined by RFC 2045. A common character set for web use is UTF-8.
Related Attributes: charset
Charsets: A space separated list of character sets (see Charset above)
Related Attributes: accept-charset
Color: An sRGB color value or a valid named color value
Related Attributes: bgcolor, color, link, text, vlink
ContentType: A valid content type/media type/MIME type as defined by RFC 2045
Related Attributes: caption
ContentTypes: A comma separated list of content types (see ContentType above)
Related Attributes: accept
Coords: A comma separated list of coordinates or lengths (see Length below). Usually used for cartesian coordinates
Related Attributes: coords
DateTime: a date and time information in ISO date format
Related Attributes: datetime
FrameTarget: Specifies which frame or window to render the content in
Common Values: _self, _top, _blank, _parent
Related Attributes: target
ID: Defines a unique token that must begin with a letter ([A-Za-z]) and may be followed by any number of letters, digits ([0-9]), hyphens ("-"), underscores ("_"), colons (":"), and periods ("."). Unlike Names (see below) IDs should not be repeated.
Related Attributes: id
IDREF: Specifies a reference to an ID token used elsewhere
Related Attributes: headers
IDREFs: Specifies a space separated list of tokens
Related Attributes: caption
InputType: Specifies the type of input element for use in a form
Valid Values: text, password, checkbox, radio, submit, reset, file, hidden, image, button
Related Attributes: type
LanguageCode: Specifies a language code as defined by RFC 1766
Common Values: en, fr, de, da, el, it
Related Attributes: hreflang, lang
Length: Specifies a size in pixels or in percentage. It should be noted that percentage values larger than 100% are allowable, but are typically not user friendly.
Related Attributes: cellpadding, cellspacing, charoff, height, width
LinkTypes: A space separated list of link types
Common Values: Alternate, Stylesheet, Start, Next, Prev, Contents, Index, Glossary, Copyright, Chapter, Section, Subsection, Appendix, Help, Bookmark
Related Attributes: rel, rev
List Styles
MediaDesc: single or comma-separated list of media descriptors
Common Values: screen, tty, tv, projection, handheld, print, print, braille, aural, all
Related Attributes: media
MultiLength: Defines a pixel, percentage, or relative length (see Length above) for an element
Related Attributes: width
MultiLengths: Defines a comma separated list of pixel, percentage, or relative lengths (see Length above) for a group of elements
Related Attributes: width
Name: Defines a token that must begin with a letter (A-Za-z) and may be followed by any number of letters, digits (0-9), hyphens ("-"), underscores ("_"), colons (":"), and periods ("."). Unlike IDs (see above) Names can be repeated.
Related Attributes: http-equiv, name
Number: Number attributes must contain one or more digits
Related Attributes: cols, colspan, maxlength, rows, rowspan, size, span, start, tabindex, value, width
Pixels: An integer representing length in pixels
Related Attributes: border, hspace, marginheight, marginwidth, size, vspace
Scope: Specifies the scope covered by a table header
Valid Values: row, col, rowgroup, colgroup
Related Attributes: border, hspace, marginheight, marginwidth, size, vspace
Script: script expression (usually JavaScript) typically dealing with document or page events
Related Attributes: onblur, onchange, onclick, ondblclick, onfocus, onkeydown, onkeypress, onkeyup, onload, onmousedown, onmousemove, onmouseout, onmouseover, onmouseup, onreset, onselect, onsubmit, onunload
Shape: Defines a shape. Typically used in image maps.
Valid Values: rect, circle, poly, default
Related Attributes: shape
StyleSheet: Defines inline style sheet data
Related Attributes: style
Text: Text differs from CDATA only in that text attributes are meant to be displayed to the user (though sometimes only as alternative content)
Related Attributes: abbr, alt, label, prompt, standby, summary, title
TFrame: Defines how the frame around a table is rendered
Valid Values: void, above, below, hsides, lhs, rhs, vsides, box, border
Related Attributes: frame
TRules: Defines table rulings between rows and columns
Valid Values: none, groups, rows, cols, all
Related Attributes: caption
URI: Defines a Uniform Resource Identifier (most often a URL)
Related Attributes: action, background, cite, classid, codebase, data, href, longdesc, profile, src, usemap
Specific Values Types: Caption alignment - specifies how/where to align a table caption
Related Attributes: caption

Default Values

While web page authors do not have to specify all possible attributes for every HTML tag on their page, the web browser must have or use some value for each of the attributes to determine how to render the viewable sections of the page. In the cases where not all of the attributes are specified, default values are used as described below:

#FIXED: A fixed attribute cannot be changed. Whether or not the author places the attribute in the HTML element or not, the value must be the fixed value specified by the DTD. This is similar to a const in many programming languages.
#IMPLIED: An implied attribute is optional. The author does not have to specify or include this value in the HTML element. It is up to the web browser to determine what value to use by default for this missing attribute. This accounts for most of the differences in how pages look in different browsers.
#REQUIRED: A required attribute must be specified in the HTML element. Failure to include the attribute will cause the page not to validate correctly, and might cause an error in the browser. In other words, no default is actually provided - the author must give one.
Value: Sometimes a single value will be specified as the default. While similar to #IMPLIED, in this case the browser does not have an option, and must use this specific default value if the author does not specify one.

Attribute Names

Below is a listing of all the valid attributes for HTML 4.01. Because the same attribute name can be used in different HTML tags to mean different things, some attributes have more than one description. Each attributes lists the name, a description, the type, related HTML tag(s), default value, and whether it is deprecated.

abbr

abbreviation for table header cell
Type: Text
Related HTML Tags: td, th
Default Value: #IMPLIED

accept

list of MIME types for file upload
Type: ContentTypes
Related HTML Tags: form, input
Default Value: #IMPLIED

accept-charset

list of supported character sets
Type: Charsets
Related HTML Tags: form
Default Value: #IMPLIED

accesskey

accessibility key character
Type: Character
Related HTML Tags: a, area, button, input, label, legend, textarea
Default Value: #IMPLIED

action

server-side form handler
Type: URI
Related HTML Tags: form
Default Value: #REQUIRED

align

caption alignment relative to table (deprecated)
Type: CAlign
Related HTML Tags: caption
Default Value: #IMPLIED

vertical or horizontal alignment of an object (deprecated)
Type: IAlign
Related HTML Tags: applet, iframe, img, input, object
Default Value: #IMPLIED

legend alignment relative to fieldset (deprecated)
Type: LAlign
Related HTML Tags: legend
Default Value: #IMPLIED

table position relative to window
Type: TAlign
Related HTML Tags: table
Default Value: #IMPLIED

alignment within table cells
Type: Custom (left | center | right | justify | char)
Related HTML Tags: col, colgroup, tbody, td, tfoot, th, thead, tr
Default Value: #IMPLIED

block element alignment (deprecated)
Type: Custom (left | center | right | justify)
Related HTML Tags: div, h1, h2, h3, h4, h5, h6, p
Default Value: #IMPLIED

horizontal rule alignment (deprecated)
Type: Custom (left | center | right)
Related HTML Tags: hr
Default Value: #IMPLIED

alink (deprecated)

color of selected links
Type: Color
Related HTML Tags: body
Default Value: #IMPLIED

alt

short description (deprecated)
Type: Text
Related HTML Tags: applet
Default Value: #IMPLIED

short description
Type: Text
Related HTML Tags: area, img
Default Value: #REQUIRED

short description
Type: CDATA
Related HTML Tags: input
Default Value: #IMPLIED

archive

comma-separated archive list (deprecated)
Type: CDATA
Related HTML Tags: applet
Default Value: #IMPLIED

space-separated list of URIs
Type: CDATA
Related HTML Tags: object
Default Value: #IMPLIED

axis

comma-separated list of related headers
Type: CDATA
Related HTML Tags: td, th
Default Value: #IMPLIED

background (deprecated)

texture tile (image) for document background
Type: URI
Related HTML Tags: body
Default Value: #IMPLIED

bgcolor (deprecated)

document background color
Type: Color
Related HTML Tags: body
Default Value: #IMPLIED

background color for cells
Type: Color
Related HTML Tags: table
Default Value: #IMPLIED

cell background color
Type: Color
Related HTML Tags: td, th
Default Value: #IMPLIED

background color for row
Type: Color
Related HTML Tags: tr
Default Value: #IMPLIED

border

link border width (deprecated)
Type: Pixels
Related HTML Tags: img, object
Default Value: #IMPLIED

controls frame width around table
Type: Pixels
Related HTML Tags: table
Default Value: #IMPLIED

cellpadding

spacing within cells
Type: Length
Related HTML Tags: table
Default Value: #IMPLIED

cellspacing

spacing between cells
Type: Length
Related HTML Tags: table
Default Value: #IMPLIED

char

alignment character; useful for lining up tables of numbers on the decimal point
Type: Character
Related HTML Tags: col, colgroup, tbody, td, tfoot, th, thead, tr
Default Value: #IMPLIED

charoff

offset for alignment char
Type: Length
Related HTML Tags: col, colgroup, tbody, td, tfoot, th, thead, tr
Default Value: #IMPLIED

charset

character encoding of linked resource
Type: Charset
Related HTML Tags: a, link, script
Default Value: #IMPLIED

checked

for radio buttons and checkboxes
Type: Custom (checked)
Related HTML Tags: input
Default Value: #IMPLIED

cite

URI for source document or message
Type: URI
Related HTML Tags: blockquote, q
Default Value: #IMPLIED

info on reason for change
Type: URI
Related HTML Tags: del, ins
Default Value: #IMPLIED

class

space-separated list of classes
Type: CDATA
Related HTML Tags: all elements except base, basefont, head, html, meta, param, script, style, title
Default Value: #IMPLIED

classid

identifies an implementation (usually source code)
Type: URI
Related HTML Tags: object
Default Value: #IMPLIED

clear (deprecated)

control of text flow following a line break
Type: Custom (left | all | right | none)
Related HTML Tags: br
Default Value: "none"

code (deprecated)

applet class file
Type: CDATA
Related HTML Tags: applet
Default Value: #IMPLIED

codebase

optional base URI for applet (deprecated)
Type: URI
Related HTML Tags: applet
Default Value: #IMPLIED

base URI for classid, data, or archive
Type: URI
Related HTML Tags: object
Default Value: #IMPLIED

codetype

content type for source code
Type: ContentType
Related HTML Tags: object
Default Value: #IMPLIED

color (deprecated)

text color
Type: Color
Related HTML Tags: basefont, font
Default Value: #IMPLIED

cols

list of lengths for frameset
Type: MultiLengths
Related HTML Tags: frameset
Default Value: #IMPLIED

number of text columns in a textarea
Type: NUMBER
Related HTML Tags: textarea
Default Value: #REQUIRED

colspan

number of columns spanned by cell
Type: NUMBER
Related HTML Tags: td, th
Default Value: "1"

compact (deprecated)

reduced inter-item spacing, display list in a compact manner
Type: Custom (compact)
Related HTML Tags: dir, dl, menu, ol, ul
Default Value: #IMPLIED

content

associated information about the document
Type: CDATA
Related HTML Tags: meta
Default Value: #REQUIRED

coords

for use with client-side image maps
Type: Coords
Related HTML Tags: a
Default Value: #IMPLIED

comma-separated list of lengths definint a shape
Type: Coords
Related HTML Tags: area
Default Value: #IMPLIED

data

reference to object's data
Type: URI
Related HTML Tags: object
Default Value: #IMPLIED

datetime

date and time of change
Type: Datetime
Related HTML Tags: del, ins
Default Value: #IMPLIED

declare

declare but don't instantiate flag
Type: Custom (declare)
Related HTML Tags: object
Default Value: #IMPLIED

defer

user agent may defer execution of script
Type: Custom (defer)
Related HTML Tags: script
Default Value: #IMPLIED

dir

direction for weak/neutral text
Type: Custom (ltr | rtl)
Related HTML Tags: all elements except applet, base, basefont, bdo, br, frame, frameset, iframe, param, script
Default Value: #IMPLIED

directionality
Type: Custom (ltr | rtl)
Related HTML Tags: bdo
Default Value: #REQUIRED

disabled

unavailable in this context
Type: (disabled)
Related HTML Tags: button, input, optgroup, option, select, textarea
Default Value: #IMPLIED

enctype

encoding type
Type: ContentType
Related HTML Tags: form
Default Value: "application/x-www-form-urlencoded"

face (deprecated)

comma-separated list of font names
Type: CDATA
Related HTML Tags: basefont, font
Default Value: #IMPLIED

for

matches field related ID value
Type: IDREF
Related HTML Tags: label
Default Value: #IMPLIED

frame

which parts of frame to render
Type: TFrame
Related HTML Tags: table
Default Value: #IMPLIED

frameborder

request frame borders
Type: Custom (1 | 0)
Related HTML Tags: frame, iframe
Default Value: "1"

headers

list of id's for header cells
Type: IDREFS
Related HTML Tags: td, th
Default Value: #IMPLIED

height

initial applet height (deprecated)
Type: Length
Related HTML Tags: applet
Default Value: #REQUIRED

frame height
Type: Length
Related HTML Tags: iframe
Default Value: #IMPLIED

override height
Type: Length
Related HTML Tags: img, object
Default Value: #IMPLIED

height for cell (deprecated)
Type: Length
Related HTML Tags: td, th
Default Value: #IMPLIED

href

URI for linked resource
Type: URI
Related HTML Tags: a, area, link
Default Value: #IMPLIED

URI that acts as base URI
Type: URI
Related HTML Tags: base
Default Value: #IMPLIED

hreflang

language code for linked resource
Type: LanguageCode
Related HTML Tags: a, link
Default Value: #IMPLIED

hspace (deprecated)

horizontal gutter
Type: Pixels
Related HTML Tags: applet, img, object
Default Value: #IMPLIED

http-equiv

HTTP response header name
Type: NAME
Related HTML Tags: meta
Default Value: #IMPLIED

id

document-wide unique id
Type: ID
Related HTML Tags: all elements except base, head, html, meta, script, style, title
Default Value: #IMPLIED

ismap

use server-side image map
Type: Custom (ismap)
Related HTML Tags: img, input
Default Value: #IMPLIED

label

for use in hierarchical drop-down menus
Type: Text
Related HTML Tags: optgroup
Default Value: #REQUIRED

for use in hierarchical drop-down menus
Type: Text
Related HTML Tags: option
Default Value: #IMPLIED

lang

language code
Type: LanguageCode
Related HTML Tags: all elements except applet, base, basefont, br, frame, frameset, iframe, param, script
Default Value: #IMPLIED

language (deprecated)

predefined script language name (e.g., "VBScript")
Type: CDATA
Related HTML Tags: script
Default Value: #IMPLIED

link (deprecated)

color of links
Type: Color
Related HTML Tags: body
Default Value: #IMPLIED

longdesc

link to long description (complements title)
Type: URI
Related HTML Tags: frame, iframe
Default Value: #IMPLIED

link to long description (complements alt)
Type: URI
Related HTML Tags: img
Default Value: #IMPLIED

marginheight

margin height in pixels
Type: Pixels
Related HTML Tags: frame, iframe
Default Value: #IMPLIED

marginwidth

margin widths in pixels
Type: Pixels
Related HTML Tags: frame, iframe
Default Value: #IMPLIED

maxlength

maximum number of characters for text fields
Type: NUMBER
Related HTML Tags: input (type text only)
Default Value: #IMPLIED

media

describes the media type this link is meant to be viewed on
Type: MediaDesc
Related HTML Tags: link
Default Value: #IMPLIED

designed for use with these media
Type: MediaDesc
Related HTML Tags: style
Default Value: #IMPLIED

method

HTTP method used to submit the form
Type: Custom (GET | POST)
Related HTML Tags: form
Default Value: GET

multiple

allows multiple selection of items in a list
Type: Custom (multiple)
Related HTML Tags: select
Default Value: #IMPLIED

name

named link end (bookmark or inner-document link)
Type: CDATA
Related HTML Tags: a
Default Value: #IMPLIED

allows applets to find each other (deprecated)
Type: CDATA
Related HTML Tags: applet
Default Value: #IMPLIED

name of form field for scripting
Type: CDATA
Related HTML Tags: button, textarea
Default Value: #IMPLIED

name of form for scripting
Type: CDATA
Related HTML Tags: form
Default Value: #IMPLIED

name of frame for targetting
Type: CDATA
Related HTML Tags: frame, iframe
Default Value: #IMPLIED

name of image for scripting
Type: CDATA
Related HTML Tags: img
Default Value: #IMPLIED

submit as part of form
Type: CDATA
Related HTML Tags: input, object
Default Value: #IMPLIED

for reference by usemap
Type: CDATA
Related HTML Tags: map
Default Value: #REQUIRED

property name
Type: CDATA
Related HTML Tags: param
Default Value: #REQUIRED

field name
Type: CDATA
Related HTML Tags: select
Default Value: #IMPLIED

metainformation name
Type: NAME
Related HTML Tags: meta
Default Value: #IMPLIED

nohref

this region of an image map has no action
Type: Custom (nohref)
Related HTML Tags: area
Default Value: #IMPLIED

noresize

allow users to resize frames?
Type: Custom (noresize)
Related HTML Tags: frame
Default Value: #IMPLIED

noshade (deprecated)

use a 3D effect?
Type: Custom (noshade)
Related HTML Tags: hr
Default Value: #IMPLIED

nowrap (deprecated)

suppress word wrap
Type: Custom (nowrap)
Related HTML Tags: td, th
Default Value: #IMPLIED

object (deprecated)

serialized applet file
Type: CDATA
Related HTML Tags: applet
Default Value: #IMPLIED

onblur

the element lost the focus
Type: Script
Related HTML Tags: a, area, button, input, label, select, textarea
Default Value: #IMPLIED

onchange

the element value was changed
Type: Script
Related HTML Tags: input, select, textarea
Default Value: #IMPLIED

onclick

a pointer button was clicked
Type: Script
Related HTML Tags: all elements except applet, base, basefont, bdo, br, font, frame, frameset, head, html, iframe, isindex, meta, param, script, style, title
Default Value: #IMPLIED

ondblclick

a pointer button was double clicked
Type: Script
Related HTML Tags: all elements except applet, base, basefont, bdo, br, font, frame, frameset, head, html, iframe, isindex, meta, param, script, style, title
Default Value: #IMPLIED

onfocus

the element got the focus
Type: Script
Related HTML Tags: a, area, button, input, label, select, textarea
Default Value: #IMPLIED

onkeydown

a key was pressed down
Type: Script
Related HTML Tags: all elements except applet, base, basefont, bdo, br, font, frame, frameset, head, html, iframe, isindex, meta, param, script, style, title
Default Value: #IMPLIED

onkeypress

a key was pressed and released
Type: Script
Related HTML Tags: all elements except applet, base, basefont, bdo, br, font, frame, frameset, head, html, iframe, isindex, meta, param, script, style, title
Default Value: #IMPLIED

onkeyup

a key was released
Type: Script
Related HTML Tags: all elements except applet, base, basefont, bdo, br, font, frame, frameset, head, html, iframe, isindex,