Boolean Attribute Type

The Boolean Attribute Type is a data type declared in the DTD as XML 1.0 type Enumeration.

Specific Attributes with Type Boolean

1. checked:
   This is declared on the elements: input type="checkbox", input type="radio"
2. declare:
   This is declared on the element: object
3. defer:
   This is declared on the element: script
4. disabled:
   This is declared on the elements: input, textarea, select, optgroup, option, button
5. ismap:
   This is declared on the elements: img, input type="image"
6. multiple:
   This is declared on the element: select
7. nohref:
   This is declared on the element: area
8. readonly:
   This is declared on the elements: input type="text", input type="password", textarea
9. selected:
   This is declared on the element: option

Common Attributes with Type Boolean

There are no Common Attributes with type Boolean.

Attribute Value for Type Boolean

A Boolean attribute. This is a type assigned to certain optional "on/off" attributes - if present, the attribute should be given its own name as its value, e.g. checked="checked"

The Boolean Attribute Type is a special case of the Enumeration Attribute Type where only one value is possible for each attribute: if present, the attribute must be given its own name as its value, e.g. selected="selected".