DOCBOOK: Invisible tech symbols

[Tomek Kaczanowski]

Hi,

I'm new to DocBook, and I have problem with tech symbols. I have a
file like this:

<?xml version='1.0' encoding='ISO-8859-2'?>
<!DOCTYPE article PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN"
"file://c:\docbook\dtd\docbookx.dtd" [
<!ENTITY % ISOtech PUBLIC "ISO 8879:1986//ENTITIES General Technical//EN"
 "file://c:\docbook\dtd\ent\iso-tech.ent">
]>
...
...
<para>&forall; &and; &cap; &infin;</para>
...

The file is well-formed and valid, it produces nice .html and .pdf but
some symbols ("forall" and "and") are invisible (pdf) or look like
small squares (html). Why is it so and how can I fix it ?

And one more thing. For such a newbies like me, it would be very
helpful if someone added a simple example of using symbols to the
DocBook: The Definitive Guide - there are lists of those
%iso_whatever% (DocBook Character Entity Reference) but no example (or
maybe I overlooked it ?). It took me some time to figure out what to do with them.

thanks for any suggestions
 Tomek Kaczanowski
mailto:[EMAIL PROTECTED]