*For discussion*

Sometimes it happens that a file satisfies multiple conditions of different rules.
These rules can't be merged because one may be a bit more fitting than the other.
On the other hand, when both match, the classification is basically duplicated.

For these cases, I suggest that we have a <with-tag> sub-condition for the <has-hint> and <has-classification> conditions.

            <when>
                <xmlfile public-id=".*JBoss.+DTD Java EE.+5.*"/>
                <not>
                    <has-classification>
                        <with-tag name="jboss-eap"/>
                    </has-classification>
                </not>
            </when>

An alternative, shorter than the above, could be:

     <hint ... preventDuplication="line, any-tag"> ...
     <classification ... preventDuplication="title, all-tags"> ...

which would only apply the classification if it would not create a duplication in certain attributes of the classification.
The attributes to check for potential duplication would be:

• line - the same line already has a hint
• title - there already is a hint/classification with the same title
• any-tag - there already is a hint/classification which has any of the tags this new hint/classification would have.
• all-tags - there already is a hint/classification which has all of the tags this new hint/classification would have.