Clarify that all fields listed are optional.

dbase_setup.rst

@@ -78,8 +78,7 @@ http://pubmlst.org/cgi-bin/bigsdb/bigsdb.pl?db=pubmlst_neisseria_isolates
 is the URL of the front page of the PubMLST Neisseria isolate database whose
 configuration settings are stored in 
 /etc/bigsdb/dbases/pubmlst_neisseria_isolates. This database sub-directory
-contains a number of files (hyperlinks lead to the files used on the Neisseria
-database):
+contains a number of optional files:
 
 * :download:`config.xml <conf/config.xml>` - the database configuration file.
   Fields defined here correspond to fields in the isolate table of the
@@ -118,9 +117,8 @@ database):
   in an automated E-mail when granting access to a user who has requested
   access to the database using the site-wide account system (where 
   auto-registration is not enabled).
-* registration.html - optional file containing text that will appear on login
-  page for the current database. Appear right before "Log in" button.
-  HTML markup can be used within this text.
+* registration.html - HTML markup for text that will appear on the login
+  page for the current database. This appears right before the "Log in" button.
 
 The header and footer files can alternatively be placed in the root directory 
 of the web site, or in /etc/bigsdb, for site-wide use. If files exist in