Html optgroup tag

The HTML <optgroup> tag is used for grouping related options within your select list. This makes it easier for users to comprehend the options when looking at a large list.

<select>
<optgroup label="Australia">
<option value ="sydney">Sydney</option>
<option value ="melbourne">Melbourne</option>
</optgroup>
<optgroup label="New Zealand">
<option value ="cromwell">Cromwell</option>
<option value ="queenstown">Queenstown</option>
</optgroup>
</select>

Element-Specific Attributes

The following table shows the attributes that are specific to this tag/element.

Attribute	Description
disabled	Disables the group of input controls. The form control won't accept changes from the user. It also cannot receive focus and will be skipped when tabbing. This is a boolean attribute. If the attribute is present, its value must either be the empty string or a value that is an ASCII case-insensitive match for the attribute's canonical name, with no leading or trailing whitespace (i.e. either disabled or disabled="disabled"). Possible values:      -  [Empty string]      -  disabled
label	Specifies a label for the option group. This attribute must be specified. Its value gives the name of the group.