How do you create a smaller mapping

I've got 2 fbx maya blend shape files.
One file has all the keyed phoneme's that matches the default Batch export.txt list. The other maya fbx file has a reduced amount of keyed blendshapes, that still follows the.txt.
Would simply adding a "//" to a phoneme listing work?
Example> 76 AH 495 >> 76 //AH 495

Thanks
FRank