DOCBOOK: entitiy sharing

["Dombrowski, James" <James dot Dombrowski at compuware dot com>]

We are using Adept 8.2 on Windows NT with a customized version of the
DocBook DTD. We are writing documentation for a group of small software
applications that all work together, and thus they share quite a few menu
items, fields and functions. Occasionally, some of these items appear on
more than one screen in an application, and must be documented or described
more than once in a particular document.

Here's the problem: If we use file entities, we can share them easily among
documents, but we can only use a file entity once in a document, or we get
errors due to multiple use of the ID/IDREF attributes. If we use text
entities (which provide for multiple use within a document), the only way we
know of to share them among documents is to manually copy the entity
declarations to the prologues of the other files (thus defeating our goal of
single-sourcing everything).

Are we missing something? Is there a process that will allow us to share
this data among documents, as well as use it more than once in a document if
needed?