Obscuration
The difference between true proof and apparent proof due to dissolved solids in the spirits. These are solid materials in spirits that prevent obtaining the true proof.

Other than standard wine
Wines products that are classified in 27 CFR Part 24 Subpart J as not standard wine, including nonbeverage wine products, heavy bodied blending wine, vinegar stock and artificially flavored wine.  A formula is required for the production of Other than Standard Wine.

Operating permit
For Distilled Spirits:  The document issued pursuant to 26 U.S.C. 5171(d), authorizing the person named in the document to engage in the business or operation described in the document.