Standard weights
Standard weights are defined by certificating authorities. Standard weights in the US come from this document, page 29
http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/0/d1ee786f363e795286256eee0061e9a6/$FILE/AC120-27D.pdf
I have flown for a half dozen carriers in different parts of the world and each carriers manuals clearly defined the approved weight and balance program. It was my experience that standard weights always favor the airline companies and a full aircraft at close to gross weight on the load sheet, is almost certainly over gross. The thing to remember is that standard weights are a statistical derivation not guaranteed to be 100% accurate 100% of the time.
I certainly keep it in mind, especially at high gross weights when there is no FLEX.