Type of Cross-Reference
Type of element that is the target of the cross-reference (for example, a Figure (“fig”), an Author Note (“author-note”), or a Bibliographic Reference (“bibr”). The values may be used for type-specific processing or validation.
The <xref> element may be used to reference anything that has an @id attribute. This single element takes the place of the many named types of references (such as figure references, table references, and footnote references) that are common in many journal tag sets. This attribute preserves the information from such tag sets concerning the type of element to which the cross-reference is pointing.
Used on Element: <xref>
|Text, numbers, or special characters||The type of element to which the reference points, for example, “fig” to indicate that the reference points to a figure (<fig>).|
|Restriction||@ref-type is an optional attribute; there is no default.|
This attribute is designed to accept any text as its value, since nearly any element in an XML article may be the target of a link. Typical values for this attribute include:
Biography (typically of a contributor).
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... <p>... The third nucleotide (CG<bold>A</bold>) at codon 529, which is a specific nucleotide of <italic>M. tuberculosis</italic> (<xref ref-type="bibr" rid="B8">8</xref>, <xref ref-type="bibr" rid="B11">11</xref>), was not clearly determined ...</p> ...