The Directory element may contain a descendent element called Extract which in itself can contain Pattern elements. However, these Pattern elements are not the same as Expression Patterns, so actually, the Directory Pattern element needs to be renamed in order to distinguish between them. Let's call the new one a "Segment". The difference between Segment and Pattern is that Segment are self contained Regexes, whereas Patterns can be collated together as a group.
The Directory element may contain a descendent element called Extract which in itself can contain Pattern elements. However, these Pattern elements are not the same as Expression Patterns, so actually, the Directory Pattern element needs to be renamed in order to distinguish between them. Let's call the new one a "Segment". The difference between Segment and Pattern is that Segment are self contained Regexes, whereas Patterns can be collated together as a group.