abs_mstr stores the shipment details. It could be pre-shippers or shippers. The abs_id has a "p" prefixed for pre-shippers and has the shipper number for shippers. The abs_status field will tell you if the shipper is created, confirmed and invoiced.
The way mfg/pro stores records in this table is not the best, since the parent item or container as well as line-items of the shipper are stored in the same table. If the volume is too huge, it takes lot of time to query and show the results.
HTH,
AJ.
