Handling of "Coatings" in IFC 4.3 are inconsistent. Propose alternative.

Since coatings - usually, but not exclusively, liquid-based solutions applied directly to the surface of the supporting material (like paint!), but NOT a "Covering" which may be a material with enough thickness to be in sheet form or thicker and applied adjacently or adhered - are common across a wide range of objects, suggest moving all indication of coating to "IfcSurfaceFeature" (added with infrastructure expansion) and made applicable to ALL elements. Need changes in documentation accordingly.