Hi Mark congratulations this is so much better in describing digit maps than the admin guide but I may be misreading your Digit map format on p6 where you state that "It is structured as a series of rules that are read from left to right. The OBi will apply the first rule that matches the format of the dialed number,". My understanding that while this applies to call routing that digit map rules are read concurrently and not sequentially and the best matched rule is returned. For example the guide quotes rules
1xxx|123x would both match 1234 but 123x would be returned rather than 1xxx because it is a better match even thought it is not the first match if read left to right.
Anyway a great effort and with your other guides highlights the flexibility of the obi .