elements. The value of the "anchor" and "target" attributes should be
   formatted according to the token syntax in Section 2.1.

   If used as an empty element, e.g.,

       according to the token syntax in <xref target="xml_basics" />.

   then the XML application inserts an appropriate phrase during
   processing, such as "Section 2.1" or "<a href="#xml_basics">XML
   Basics".

   If used with content, e.g.,

       conforming to <xref target="refs.RFC2223">RFC 2223.

   then the XML application inserts an appropriate designation during
   processing, such as "RFC 2223 [2]" or "<a href="#refs.RFC2223">RFC
   2223". Although the XML application decides what "an appropriate
   designation" might be, its choice is consistent throughout the
   processing of the document.

2.3.1.5 The eref Element

   The "eref" element is used to reference external documents. The
   mandatory "target" attribute is a URI [4], e.g.,

       <eref target="http://metalab.unc.edu/xml/">Cafe con Leche

   Note that while the "target" attribute is always present, the "eref"
   element may be empty, e.g.,

       <eref target="http://invisible.net/" />

   and the XML application inserts an appropriate designation during
   processing such as "[9]" or "<a
   href="http://invisible.net/">http://invisible.net/".






 
RFC 2629            Writing I-Ds and RFCs using XML            June 1999


2.3.1.6 The iref Element

   The "iref" element is used to add information to an index. The
   mandatory "item" attribute is the primary key the information is
   stored under, whilst the optional "subitem" attribute is the
   secondary key, e.g.,

       <iref item="indexing" subitem="how to" />

   Finally, note that the "iref" element is always empty -- it never
   contains any text.

2.3.1.7 The vspace Element

   The "vspace" element, which may occur only inside the "t" element, is
   used by the author to provide formatting guidance to the XML
   application. There is an attribute, "blankLines", that indicates the
   number of blank lines that should be inserted. A physical linebreak
   is specified by using the default value, "0".

   In addition, the "vspace" element can be used to force a new physical
   paragraph within a list item, e.g.,

       <list style="numbers">
           This is list item.
              <vspace blankLines="1" />
              This is part of the same list item,
              although when displayed, it appears
              as a separate physical paragraph.
       

   An XML application producing a text version of the document should
   exercise care when encountering a value for "blankLines" that causes
   a pagebreak -- in particular, if a "vspace" element causes a
   pagebreak, then no further blank lines should be inserted. This
   allows authors to "force" a pagebreak by using an arbitrarily large
   value, e.g., "blankLines='100'".

   Finally, note that the "vspace" element is always empty -- it never
   contains any text.












 
RFC 2629            Writing I-Ds and RFCs using XML            June 1999