Underline Start


The start of a milestone-created underline


The Underline Start and Underline End elements enable creation of underlines in content, most commonly in mathematical content, where a normal Underline tag ( <underline>) would break the XML well-formedness rule that no two elements may overlap. The underline created using these two elements can have arbitrary start and end points because the start and end elements are paired through the use of the unique identifiers (IDs), not as the start and end of a single element. For example, in the text “ABCD”, if the text “ABC” is the be overlined and the text “CD” is to be underlined, ordinary underlining with <underline> would create invalid tag overlap. The text could be correctly tagged, using the Underline Start and Underline End elements as:

<overline-start id="overline"/>AB
<underline-start id="ul1"/>C
<overline-end rid="ov1"/>D
<underline-end rid="ul1"/>


id Identifier

Related Elements

The Underline is used for ordinary underlining. For special underlines, involving problems with element overlap, use the milestone elements Underline Start and Underline End.

When a milestone underlining technique is used, the start of underline will be marked by an Underline Start element and the end of underline will be marked by an Underline End element.

Model Description

This is an EMPTY element, that is, it has no content, only attributes.

Tagged Example

No sample is available at this time.