> maybe I'm just not noticing a very basic thing (sorry, in this
> case), but I have some trouble in customization element classes
> within Roma.
> While it seems quite easy adding a completely new element to the
> content of a given element using the Add Element facility, I see no
> way to include an existing element inside anther existing element,
> as Change Class facility concerns just attribute classes.
> For example: I would like to include the <availability> element
> inside <bib> element. For the moment it seems that I can't do that
> within Roma, but I need to do it modifying the schema file directly
> and after that uploading it on Roma.
Very hasty reply, hope I get this right:
To include <availability> inside <bibl> using Roma the web interface:
0. Figure out what the content of <bibl> is by reading the P5
1. Ascertain if any of the current classes that make up the content
of <bibl> make sense for this purpose. My guess is
'model.biblPart' may make sense.
2. Navigate to the change element page for <bibl>, e.g.:
- start at the "Modules" tab
- click on the "header" module
- search for the <availability> element (luckily it's the 2nd
element, so very easy to find) and click on the element name in
the left column
3. Click the box next to 'model.biblPart' 
4. Save your schema! (I always suggest people do this often while
using the web interface :-)
5. Although I think this particular change is likely to work, this is
the kind of change that will often break DTDs.
 This should stick something like the following into your ODD
<elementSpec ident="availability" module="header" mode="change">