<location id=id>text<\location>
Or:
<location id=id|text|
Where:
The identifier for the current location, which can be used as a destination for hyperlinks.
The block of text where you want to assign the ID.
The <location> element is not needed at locations where there is already an element (such as <hometopic> or <figure>) that has a built-in ID or accommodates an author-defined id parameter.
Cross-references created with the <xref> element substitute the text between the <location> start and end tag for the <xref> element.