IMPLEMENTATION REQUIREMENTS

The HTMLElement interface has one new DOM attribute:

  attribute boolean spellcheck;

On getting, the "spellcheck" DOM attribute returns a value as
determined by the following algorithm.

 * If the element has a "spellcheck" content attribute with the ASCII
   case-insensitive value "true", then the DOM attribute must return
   true.

 * Otherwise, if the element has a "spellcheck" content attribute with
   the ASCII case-insensitive value "false", then the DOM attribute
   must return false.

 * Otherwise, it must return the UA default value for that element. If
   the UA default for that element is to inherit from its parent
   element, then it must return the same as its parent's "spellcheck"
   DOM attribute.

Note: The "spellcheck" DOM attribute is not affected by user
preferences, and therefore might not reflect the actual spellchecking
state.

The the DOM attribute is set, the element's "spellcheck" content
attribute must be set to the literal value "true" if the attribute is
being set to the "true" value, and "false" otherwise.

To determine if a word, sentence, or other piece of text is to have
spelling and/or grammar checking enabled, the UA must use the
following algorithm:

 1. If the user has disabled the checking for this text, or if the
    text is readonly, or if the text is disabled, then the checking is
    disabled.

 2. Otherwise, if the user has forced the checking for this text to
    always be enabled, then the checking is enabled.

 3. Otherwise, if the element with which the text is associated has a
    "spellcheck" content attribute, then: if that attribute has the
    ASCII case-insensitive value "true", then checking is enabled;
    otherwise, if that attribute has the ASCII case-insensitive
    "false", then checking is disabled; otherwise, move on to the next
    step.

 4. Otherwise, if the element with which the text is associated has an
    ancestor element with a "spellcheck" attribute set to one of the
    ASCII case-insensitive values "true" or "false", then, if the
    nearest such ancestor has its attribute set to the ASCII
    case-insensitive value "true", then checking is enabled;
    otherwise, if the nearest such ancestor has its attribute set to
    the ASCII case-insensitive value "false", then checking is
    disabled; otherwise, move on to the next step.

 5. The UA default for this element must be used. The UA default can
    vary based on heuristics, e.g. whether the element is enabled or
    not.

For text that is part of text or CDATA nodes, the element with which
the text is associated is the element that is the immediate parent of
the start of the word, sentence, or other piece of text. For text in
attributes, it is the element with which the attribute is
associated. For text in text fields, it is the relevant input or
textarea element.

Examples:

   The element with id "a" in the following example would be the one
   used to determine if the word "Hello" is spell-checked. It this
   example, it would not be.

      <div contenteditable="true">
        <span spellcheck="false" id="a">Hell</span><em>o!</em>
      </div>

   The element "b" in the following example would have spell checking
   enabled (not disabled, because of the leading " " character, and
   not the UA default, because the grandparent explicitly enables it).

      <p spellcheck="true">
       <label>Name: <input spellcheck=" false" id="b"></label>
      </p>

If the checking is enabled for a word/sentence/text, the UA should
indicate spelling and/or grammar errors in that text. UAs should take
into account the other semantics given in the document when suggesting
spelling and grammar corrections. UAs should use the language of the
element to determine what spelling and grammar rules to use. (Language
information can come from the "lang" and "xml:lang" attributes,
Content-Language HTTP headers, or other sources. q.v.) UAs should use
input element attributes such as pattern to ensure that the resulting
value is valid.

If spellchecking is disabled, the UA should not indicate spelling or
grammar errors for that text.



AUTHOR REQUIREMENTS

Elements may have a new attribute specified, "spellcheck".  If
specified, it must have either the value "true" or the value "false"
(ASCII case-INsensitive). The "true" value indicates that
spellchecking is to be enabled, the "false" value indicates that
spellchecking is to be disabled. The attribute is inherited. By
default, the UA and user preferences decide if spelling checking is
enabled.

There is also a "spellcheck" DOM attribute on all elements that can be
used to quickly set the value of the content attribute dynamically, or
to check the default value for an element.

Authors should set the document's language information, to enable user
agents to accurately determine which dictionary to use when checking
the spelling or grammar of user input.