The WWP encodes links and cross-references for several different kinds of textual features, including tables of contents, errata lists, indexes, and notes. In addition, we use them for atypical features such as textual segments which are printed in a place different from their intended location in the document (for instance, dramatic scenes which are printed in the front matter with an indication that they were intended to be inserted in the third act).
Since most of our encoding involves capturing references that appear in the source text (e.g. cross-references), we tend to use <ref> rather than <ptr/> (which has no content), and have used only the rend=, target= and type= attributes. (For more detail on tables of contents, see 042.) In the future we may expand our use of linking and cross-referencing.
The WWP differs from TEI in the attribute declarations for <ptr/> and <ref>. Unlike TEI, the WWP provides a type= attribute for these elements. This list of pre-defined values reflects our areas of pointer/reference use so far. They are “err”, “correction”, and “pagenum”. Errata lists use a referencing system in which a <ref type="err"> encodes the error in the body of the text, and a <ref type="correction"> encodes the printer’s emendation in the corrigenda. The two <ref> elements point to each other using the target= attribute of <ref>, as in the example. For a more thorough discussion of errata lists see 060.
The “pagenum” value is used on <ref> in tables of contents to identify the reference as originating inside a table of contents.