1. 15 Obsolete features
    1. 15.1 Obsolete but conforming features
    2. 15.2 Non-conforming features

15 Obsolete features

15.1 Obsolete but conforming features

Features listed in this section will trigger warnings in conformance checkers.

Authors should not specify a border attribute on an img element. If the attribute is present, its value must be the string "0". CSS should be used instead.

Authors should not specify a charset attribute on a script element. If the attribute is present, its value must be an ASCII case-insensitive match for "utf-8". (This has no effect in a document that conforms to the requirements elsewhere in this standard of being encoded as UTF-8.)

Authors should not specify a language attribute on a script element. If the attribute is present, its value must be an ASCII case-insensitive match for the string "JavaScript" and either the type attribute must be omitted or its value must be an ASCII case-insensitive match for the string "text/javascript". The attribute should be entirely omitted instead (with the value "JavaScript", it has no effect), or replaced with use of the type attribute.

Authors should not specify a value for the type attribute on script elements that is the empty string or a JavaScript MIME type essence match. Instead, they should omit the attribute, which has the same effect.

Authors should not specify a type attribute on a style element. If the attribute is present, its value must be an ASCII case-insensitive match for "text/css".

Authors should not specify the name attribute on a elements. If the attribute is present, its value must not be the empty string and must neither be equal to the value of any of the IDs in the element's tree other than the element's own ID, if any, nor be equal to the value of any of the other name attributes on a elements in the element's tree. If this attribute is present and the element has an ID, then the attribute's value must be equal to the element's ID. In earlier versions of the language, this attribute was intended as a way to specify possible targets for fragments in URLs. The id attribute should be used instead.

Authors should not, but may despite requirements to the contrary elsewhere in this specification, specify the maxlength and size attributes on input elements whose type attributes are in the Number state. One valid reason for using these attributes regardless is to help legacy user agents that do not support input elements with type="number" to still render the text control with a useful width.

15.2 Non-conforming features

Elements in the following list are entirely obsolete, and must not be used by authors:

applet

Use embed or object instead.

acronym

Use abbr instead.

bgsound

Use audio instead.

dir

Use ul instead.

frame
frameset
noframes

Either use iframe and CSS instead, or use server-side includes to generate complete pages with the various invariant parts merged in.

isindex

Use an explicit form and text control combination instead.

keygen

For enterprise device management use cases, use native on-device management capabilities.

For certificate enrollment use cases, use the Web Cryptography API to generate a keypair for the certificate, and then export the certificate and key to allow the user to install them manually. [WEBCRYPTO]

listing

Use pre and code instead.

menuitem

To implement a custom context menu, use script to handle the contextmenu event.

nextid

Use GUIDs instead.

noembed

Use object instead of embed when fallback is necessary.

plaintext

Use the "text/plain" MIME type instead.

rb
rtc

Providing the ruby base directly inside the ruby element or using nested ruby elements is sufficient.

strike

Use del instead if the element is marking an edit, otherwise use s instead.

xmp

Use pre and code instead, and escape "<" and "&" characters as "&lt;" and "&amp;" respectively.

basefont
big
blink
center
font
marquee
multicol
nobr
spacer
tt

Use appropriate elements or CSS instead.

Where the tt element would have been used for marking up keyboard input, consider the kbd element; for variables, consider the var element; for computer code, consider the code element; and for computer output, consider the samp element.

Similarly, if the big element is being used to denote a heading, consider using the h1 element; if it is being used for marking up important passages, consider the strong element; and if it is being used for highlighting text for reference purposes, consider the mark element.

See also the text-level semantics usage summary for more suggestions with examples.

The following attributes are obsolete (though the elements are still part of the language), and must not be used by authors:

charset on a elements
charset on link elements

Use an HTTP `Content-Type` header on the linked resource instead.

charset on script elements (except as noted in the previous section)

Omit the attribute. Both documents and scripts are required to use UTF-8, so it is redundant to specify it on the script element since it inherits from the document.

coords on a elements
shape on a elements

Use area instead of a for image maps.

methods on a elements
methods on link elements

Use the HTTP OPTIONS feature instead.

name on a elements (except as noted in the previous section)
name on embed elements
name on img elements
name on option elements

Use the id attribute instead.

rev on a elements
rev on link elements

Use the rel attribute instead, with an opposite term. (For example, instead of rev="made", use rel="author".)

urn on a elements
urn on link elements

Specify the preferred persistent identifier using the href attribute instead.

accept on forms

Use the accept attribute directly on the input elements instead.

hreflang on area elements
type on area elements

These attributes do not do anything useful, and for historical reasons there are no corresponding IDL attributes on area elements. Omit them altogether.

nohref on area elements

Omitting the href attribute is sufficient; the nohref attribute is unnecessary. Omit it altogether.

profile on head elements

Unnecessary. Omit it altogether.

manifest on html elements

Use service workers instead. [SW]

version on html elements

Unnecessary. Omit it altogether.

ismap on input elements

Unnecessary. Omit it altogether. All input elements with a type attribute in the Image Button state are processed as server-side image maps.

usemap on input elements
usemap on object elements

Use the img element for image maps.

longdesc on iframe elements
longdesc on img elements

Use a regular a element to link to the description, or (in the case of images) use an image map to provide a link from the image to the image's description.

lowsrc on img elements

Use a progressive JPEG image (given in the src attribute), instead of using two separate images.

target on link elements

Unnecessary. Omit it altogether.

type on menu elements

To implement a custom context menu, use script to handle the contextmenu event. For toolbar menus, omit the attribute.

label on menu elements
contextmenu on all elements
onshow on all elements

To implement a custom context menu, use script to handle the contextmenu event.

scheme on meta elements

Use only one scheme per field, or make the scheme declaration part of the value.

archive on object elements
classid on object elements
code on object elements
codebase on object elements
codetype on object elements

Use the data and type attributes to invoke plugins. To set parameters with these names in particular, the param element can be used.

declare on object elements

Repeat the object element completely each time the resource is to be reused.

standby on object elements

Optimize the linked resource so that it loads quickly or, at least, incrementally.

typemustmatch on object elements

Avoid using object elements with untrusted resources.

type on param elements
valuetype on param elements

Use the name and value attributes without declaring value types.

language on script elements (except as noted in the previous section)

Omit the attribute for JavaScript; for data blocks, use the type attribute instead.

event on script elements
for on script elements

Use DOM events mechanisms to register event listeners. [DOM]

type on style elements (except as noted in the previous section)

Omit the attribute for CSS; for data blocks, use script as the container instead of style.

datapagesize on table elements

Unnecessary. Omit it altogether.

summary on table elements

Use one of the techniques for describing tables given in the table section instead.

abbr on td elements

Use text that begins in an unambiguous and terse manner, and include any more elaborate text after that. The title attribute can also be useful in including more detailed text, so that the cell's contents can be made terse. If it's a heading, use th (which has an abbr attribute).

axis on td and th elements

Use the scope attribute on the relevant th.

scope on td elements

Use th elements for heading cells.

datasrc on a, button, div, frame, iframe, img, input, label, legend, marquee, object, option, select, span, table, and textarea elements
datafld on a, button, div, fieldset, frame, iframe, img, input, label, legend, marquee, object, param, select, span, and textarea elements
dataformatas on button, div, input, label, legend, marquee, object, option, select, span, and table elements

Use script and a mechanism such as XMLHttpRequest to populate the page dynamically. [XHR]

dropzone on all elements

Use script to handle the dragenter and dragover events instead.

alink on body elements
bgcolor on body elements
bottommargin on body elements
leftmargin on body elements
link on body elements
marginheight on body elements
marginwidth on body elements
rightmargin on body elements
text on body elements
topmargin on body elements
vlink on body elements
clear on br elements
align on caption elements
align on col elements
char on col elements
charoff on col elements
valign on col elements
width on col elements
align on div elements
compact on dl elements
align on embed elements
hspace on embed elements
vspace on embed elements
align on hr elements
color on hr elements
noshade on hr elements
size on hr elements
width on hr elements
align on h1—h6 elements
align on iframe elements
allowtransparency on iframe elements
frameborder on iframe elements
framespacing on iframe elements
hspace on iframe elements
marginheight on iframe elements
marginwidth on iframe elements
scrolling on iframe elements
vspace on iframe elements
align on input elements
border on input elements
hspace on input elements
vspace on input elements
align on img elements
border on img elements (except as noted in the previous section)
hspace on img elements
vspace on img elements
align on legend elements
type on li elements
compact on menu elements
align on object elements
border on object elements
hspace on object elements
vspace on object elements
compact on ol elements
align on p elements
width on pre elements
align on table elements
bgcolor on table elements
border on table elements
bordercolor on table elements
cellpadding on table elements
cellspacing on table elements
frame on table elements
height on table elements
rules on table elements
width on table elements
align on tbody, thead, and tfoot elements
char on tbody, thead, and tfoot elements
charoff on tbody, thead, and tfoot elements
height on thead, tbody, and tfoot elements
valign on tbody, thead, and tfoot elements
align on td and th elements
bgcolor on td and th elements
char on td and th elements
charoff on td and th elements
height on td and th elements
nowrap on td and th elements
valign on td and th elements
width on td and th elements
align on tr elements
bgcolor on tr elements
char on tr elements
charoff on tr elements
height on tr elements
valign on tr elements
compact on ul elements
type on ul elements
background on body, table, thead, tbody, tfoot, tr, td, and th elements

Use CSS instead.