Normally it comes in handy that such a field is shown in a generic editor, but not when you are trying to edit its neighboring fields in the following way:
<%@ page language="java" contentType="text/html" session="false"
%><%@ taglib uri="
http://www.mmbase.org/mmbase-taglib-1.0" prefix="mm"
%><mm:cloud loginpage="login.jsp" rank="basic user">
<mm:import externid="nr" />
<mm:present referid="nr">
<mm:node number="$nr">
<mm:fieldlist type="edit">
<mm:import id="fld" reset="true"><mm:fieldinfo type="name" /></mm:import>
<mm:import id="fldname" reset="true">_<mm:fieldinfo type="name" /></mm:import>
<mm:import externid="$fldname" />
<mm:setfield name="$fld"><mm:write referid="$fldname" /></mm:setfield>
</mm:fieldlist>
<mm:redirect page="../edit.jsp" referids="nr">
<mm:param name="msg">De wijzigingen zijn bewaard.</mm:param>
</mm:redirect>
</mm:node>
</mm:present>
</mm:cloud>