Larry,
This rule is used to implement a simple version of single-stage dialling through another OBi device. Star Codes are not involved.
[1-9]x? Means any digit from 1 to 9, followed by any other digit or no digit. This is the format for speed dials 1 to 99.
Assume that you put an OBi number say pp(ob200123456) in speed dial slot 5.
Now if you dial 5*11223344556 the {([1-9]x?*(Mpli)):pp} rule will direct that call onto the OBiTALK trunk. The trunk/OBi servers will decode the 5* as the target OBi (200123456) and send 11223344556 to that target OBi.
It is then up to the target OBi OBiTALK InboundCallRoute to route that call according to its rules.
RonR suggests changing the rule to {([1-9]x?*@@.):pp}
This removes the original restriction of the number having to match Mpli in the sending OBi.