wiq Schema contains the following list of elements:

• WorkItemQuery Element
• Wiql Element
• TeamFoundationServer Element
• TeamProject Element

WorktItemQuery element contains the Work Item Query Definition.
<WorkItemQuery Version="version number">
    <Wiql />
    <TeamFoundationServer />
    <TeamProject />
</WorkItemQuery>

WorkItemQuery’s Version number must be an integer and it represents query version number.

Wiql element is a required element and contains command the make up the actual query.
For example: SELECT list FROM workitem [WHERE condition] [ORDER BY columns] [ASOF datetime].

TeamFoundationServer is another element of the schema and specifies TFS which will run the query defined in Wiql element.

TeamProject is the Team Project space with will be used for the query.