Re: [xml-dev] xml:base and fragments

[Peter Flynn <peter@silmaril.ie>]

On 05/09/2017 08:57 AM, Andrew S. Townley wrote:
[...]
> Out of curiosity, and without knowing the specifics of TEI, if you
> wanted to reference other elements or their content directly in the same
> or linked documents, how else would you do this?

It probably comes as no surprise to find that "it depends" :-)

Until the most recent version (P5), normal links within the same
document used ID/IDREF, as that comes "free" with every validating
parser. The element types ptr, ref, and link all had a @target attribute
declared as IDREFS. The element types xptr and xref had attributes to
handle Extended Pointers for out-of-document linking. I suspect many
millions of documents still using P4 continue to use these.

P5 got rid of xptr and xref, and changed @target attribute to CDATA,
which means it can now take any value, including a URI, so that's
presumably where people are getting it from (examples in the
Guidelines). The ID/IDREF mechanism is not used, apparently on the
assumption that the only thing anyone wants to do with text is put it on
the web in HTML.

There are lots of other fun things to do with links, see Chapter 16 of
the Guidelines at
http://www.tei-c.org/release/doc/tei-p5-doc/en/html/SA.html

///Peter