A transformation pattern is used to modify the calling or called number depending on what type of transformation it is. Without seeing the actual details of the transformation I can only speculate on what that specific pattern would do. My guess is that it would drop the leading digit, aka drop the 9. I base that assumption on that you have 9. as the start of the pattern and a dot is often used together with a DDI, discard digit instruction, to drop pre-dot.
One important aspect of transformations that all to often is overlooked is that it should never ever be mixed with call routing partitions and calling search spaces as that would cause undesirable results.
