Document that contrib/pgtrgm only processes ASCII alphanumeric

bmomjian · bmomjian · commit d235f828d74d · 2011-09-05T13:24:45.000-04:00
characters.

Backpatch to 9.0 and 9.1.
diff --git a/doc/src/sgml/pgtrgm.sgml b/doc/src/sgml/pgtrgm.sgml
@@ -9,7 +9,8 @@
 
  <para>
   The <filename>pg_trgm</filename> module provides functions and operators
-  for determining the similarity of text based on trigram matching, as
+  for determining the similarity of <acronym>ASCII</>
+  alphanumeric text based on trigram matching, as
   well as index operator classes that support fast searching for similar
   strings.
  </para>
