You use the Tab element to cluster a group of fields or to support one or more special controls, such as the controls that link work items, display the work item history, or to attach files.
<xs:element name="Tab" type="TabType" minOccurs="1" maxOccurs="unbounded"/>
<Tab Label="LabelText" Padding="(left, top, right, bottom)" Margin="(left, top, right, bottom)">
    <Group> . . . </Group>
    <Control> . . . </Control>
    <TabGroup> . . . </TabGroup>
    <Splitter> . . . </Splitter>
</Tab>
Attributes and Elements
The following sections describe attributes, child elements, and parent elements.
Attributes
| Attribute | Description | 
|---|---|
| Label | Required TabType attribute. The label for a set of grouped elements. | 
| Padding | Optional TabType attribute. The amount of space in pixels around the inside border of the control. | 
| Margin | Optional TabType attribute. The amount of space in pixels around the outside border of the control. | 
Child Elements
| Element | Description | 
|---|---|
| Optional. Defines a group of elements to display together on the form. | |
| Optional. Defines a field that is to appear on the form. | |
| Optional. Contains one or more Tab elements. | |
| Optional. Defines a splitter and its orientation on the form between sibling form elements. | 
Parent Elements
| Element | Description | 
|---|---|
| Optional. Contains one or more Tab elements. | 
Remarks
Tab is a required child element of TabGroup.
minOccurs="1"
maxOccurs="unbounded"
Example
<FORM>
      <Layout>
        . . . 
            <TabGroup>
              <Tab Label="Planning">
                <Group Label="Status" Padding="(0,0,0,3)">
                  <Column PercentWidth="100">
                    <Control FieldName="Microsoft.DevDiv.Importance" Type="FieldControl" Label="Importance" LabelPosition="Left" />
                    <Control FieldName="Microsoft.DevDiv.Commitment" Type="FieldControl" Label="Commitment / Confidence" LabelPosition="Left" />
                    . . .
                  </Column>
                </Group>
                </Tab>
              <Tab Label="Description">
                <Group>
                  <Column PercentWidth="100">
                    <Control FieldName="System.Description" Type="HtmlFieldControl" Label="Value Proposition Description" LabelPosition="Top" />
                  </Column >
                </Group>
              </Tab>
 . . .              
            </TabGroup>
      </Layout>
</FORM>
Element Information
| Namespace | https://schemas.microsoft.com/VisualStudio/2005/workitemtracking/typedef | 
| Schema Name | Work Item Type Definition | 
| Validation File | WorkItemTypeDefinition.xsd | 
| Element Type | TabType Complex Type | 
| Can Be Empty | Yes |