postgres/doc/src/sgml/README.links

<!-- doc/src/sgml/README.links -->

Linking within SGML documents can be confusing, so here is a summary:


Intra-document Linking
----------------------

<xref>
	use to get chapter/section number from the title of the target
	link, or xreflabel if defined at the target, or refentrytitle if target
        is a refentry;  has no close tag
	http://www.oasis-open.org/docbook/documentation/reference/html/xref.html

<link>
	use to supply text for the link, requires </link>
	http://www.oasis-open.org/docbook/documentation/reference/html/link.html

linkend=
	controls the target of the link/xref, required

endterm=
	for <xref>, allows the text of the link/xref to be taken from a
	different link target title


External Linking
----------------

<ulink>
	like <link>, but uses a URL (not a document target);  requires
	</ulink>; if no text is specified, the URL appears as the link
	text
	http://www.oasis-open.org/docbook/documentation/reference/html/ulink.html

url=
	used by <ulink> to specify the URL, required


Guidelines
----------

o  If you want to supply text, use <link>, else <xref>
o  Do not use text with <ulink> so the URL appears in printed output
o  Specific nouns like GUC variables, SQL commands, and contrib modules
   usually have xreflabels