5.2.2  References

The representation of references is modeled on the XML representation of bookmarks. There are two types of reference marks, as follows:

�        A point reference
A point reference marks a particular position in text and is represented by a single <text:reference-mark> element.

�        A range reference
A range reference marks a range of characters in text and is represented by two elements; <text:reference-mark-start> to mark the start of the range and <text:reference-mark-end> to mark the end of the range.

Every reference is identified by its name, which must be unique. In a range reference, the start and end elements must use the same reference name.

        Point References

The <text:reference-mark> element represents a point reference.

        Range References

The <text:reference-mark-start> and <text:reference-mark-end> elements represent a range reference.

In the OpenDocument schema, three elements are used to represent references instead of one element because references represented as a single XML element:

�        Cannot support overlapping references

�        Do not interact well with other elements

Take the following example:

Example: Overlapping range references

<text:p>
     <text:reference-mark-start text:name="first"/>This is an

     <text:reference-mark-start text:name="second"/>example of a sentence

     <text:reference-mark-end text:name="first"/>with overlapping references.

     <text:reference-mark-end text:name="second"/>
</text:p>

The example paragraph shows two references that cover the following text:

This overlapping structure cannot be represented using a single reference element to contain the referenced text. Similarly, a reference spanning multiple paragraphs creates the same situation as two overlapping XML elements, as does character formatting either starts or ends, but not both, within the referenced text.