The Advanced Tab Page in the Shop Order Line Detail Panel displays information about the Bill of Materials that was used to create the selected Shop Order Line. The BOM No: field displays the unique BOM number that was used to create the shop order, and the revision field displays the BOM revision that was used to create the shop order (the combination of the top level item in the shop order and the revision number can also be used to identify the specific BOM that the line was created from).
If the BOM NO and the Revision fields in the shop order line are not loaded, then the shop order line was added to the shop order manually and it was not created from an existing Bill of Materials.
More: