Thanks. How about for XF? Should the coin have at least a trace of luster in protected areas by ANA standards to be XF? I think the TPGs have been largely a positive influence on the hobby, but using luster as part of the grade is more intellectually appealing to me for my personal grade estimates regardless of what they do.
I've never seen any of their published standards, but it doesn't surprise me that they'd leave market grading out of print.
I agree with both Leadfoot and physics-fan. What you need to learn to look at are the breaks in the luster. The physical difference between AU and UNC is wear. The evidence of the wear is shown by a break in the luster. In a tough series like Franklins, many times it is the ONLY way to tell AU from UNC and sometimes EVEN VF from UNC because you are looking at detail. The key to judging detail is knowing which dates are weakly struck. My advice to you is to learn to look at the high points of the design and learn to distinguish a break in luster, and you will have found one of the keys to grading many series, especially the more difficult ones like Franklin Halves. Be able to tell wear from strike and you can separate UNC from everything else. Then you look at the detail to determine which MS grade, not the other way around.
It depends on the coin. For some half of the luster must be present for XF45, partial for XF40. For others, partial for XF45 and traces for XF40. For still others traces for XF45 and none for XF40. For still others no luster is required for either XF45 or XF40.
Don't misunderstand, there have been no grading standards published since 1987 that were not based on market grading. Even the ANA uses market grading and has, since 1987. I assume that what you are thinking of is the value aspect of grading. On that you would be correct, there are no published standards.