[Anton Voloshin <a.voloshin@postgrespro.ru>]

Hello.

While browsing character set collation documentation [1]
I've found myself a bit puzzled by unfamiliar terminology:
 > of course a domain over a collatable data type is collatable

Of course, it only takes a search or two to find out the exact
meaning of "domain" in this context, but I think it would be useful
to make this word a link to the relevant section as a help for less 
experienced users like myself.

I've attached a patch that does that. Please let me know whether this 
fix is desirable and correct (I'm new to Postgres) and if there is a 
better way of suggesting an improvement for the documentation.

[1] https://www.postgresql.org/docs/current/collation.html

-- 
Anton Voloshin
Postgres Professional: https://www.postgrespro.com
Russian Postgres Company

Attachments:

collation-domains-link.patch (text/plain, 795B) download
diff --git a/doc/src/sgml/charset.sgml b/doc/src/sgml/charset.sgml
index 1b00e543a6..300a0d83d4 100644
--- a/doc/src/sgml/charset.sgml
+++ b/doc/src/sgml/charset.sgml
@@ -346,7 +346,8 @@ initdb --locale=sv_SE
     collation.  (The built-in collatable data types are
     <type>text</type>, <type>varchar</type>, and <type>char</type>.
     User-defined base types can also be marked collatable, and of course
-    a domain over a collatable data type is collatable.)  If the
+    a <link linkend="domains">domain</link> over a collatable data type
+    is collatable.)  If the
     expression is a column reference, the collation of the expression is the
     defined collation of the column.  If the expression is a constant, the
     collation is the default collation of the data type of the