HTML scheme Attribute
The obsolete HTML scheme attribute was historically used on the <meta> element to provide additional information about how the value of its content attribute should be interpreted.
scheme attribute is obsolete and should not be used in modern HTML. Use the metadata format required by the particular metadata system and include any necessary scheme information as part of the field or value.
Historical Syntax
The scheme attribute was placed on a <meta> element and used together with attributes such as name and content.
<meta name="identifier" content="1580081754" scheme="ISBN">In this example, content provides the metadata value while scheme="ISBN" supplies additional information about how that value should be interpreted.
Historical Elements
The obsolete scheme attribute was associated with the <meta> element.
| Element | Historical Purpose |
|---|---|
<meta> |
Provided additional information about the format or interpretation of a metadata value. |
Historical Use
The <meta> element represents metadata that is not normally displayed as page content. The historical scheme attribute could provide a format name or other information that helped describe how a metadata value should be interpreted.
<meta name="identifier" content="1580081754" scheme="ISBN">Here, the metadata field is named identifier, its value is supplied by content, and scheme indicates that the value uses an ISBN identification scheme.
The exact meaning of a scheme depended on the metadata system using the field. The attribute did not affect the visual appearance of the webpage.
Why It Became Obsolete
The scheme attribute was removed from modern authoring because metadata can be expressed without a separate general-purpose HTML attribute for declaring the interpretation of each value.
Current HTML guidance is to use only one scheme for a metadata field or make the scheme declaration part of the metadata value when it is necessary. Different metadata systems can also define their own rules for representing and interpreting values.
Modern Alternative
There is no single modern HTML attribute that directly replaces scheme. Remove the obsolete attribute and follow the requirements of the metadata system being used.
Historical HTML
<meta name="identifier" content="1580081754" scheme="ISBN">Modern Approach
If the metadata field already has a defined format, the separate scheme attribute can be omitted:
<meta name="identifier" content="1580081754">If information about the scheme must be preserved, the metadata system may require it to be incorporated into the field or value instead:
<meta name="identifier" content="ISBN: 1580081754">scheme attribute.
Legacy Browser Support
The scheme attribute appeared in older HTML specifications and may still be exposed by browsers for compatibility with legacy documents.
Modern webpages should not rely on the attribute. Current HTML identifies scheme on <meta> as obsolete, and user agents are encouraged to process recognized metadata without depending on it.
For additional information about historical browser compatibility, visit Can I Use? . Search for the HTML element or attribute you want to check. Search results can include related HTML features, element attributes, APIs, and other technologies, so select the result that most closely matches the legacy feature you are researching.
Related Attributes
Other attributes associated with metadata include:
name- Identifies the type of metadata represented by certain<meta>elements.content- Supplies the value of metadata represented by a<meta>element.http-equiv- Identifies certain pragma directives represented by a<meta>element.charset- Declares the character encoding of the HTML document.profile- An obsolete attribute historically used on<head>for metadata profiles.
Specifications
The scheme attribute on the <meta> element is obsolete and must not be used by authors. Current guidance is to use only one scheme per field or make the scheme declaration part of the value. See the WHATWG HTML Living Standard for information about obsolete and non-conforming features.