I think a kind of matrix can be constructed, with some of the options and reactions:
Options
1a. Don't allow any ranked references
1b. Allow only 1 ranked reference
1c. Allow multiple ranked references
2a. Ranked reference must be accompanied by ABX to 95% confidence
2b. Ranked reference does not need to be accompanied by ABX results
3a. Score of ranked reference is not lower than another properly-ranked codec
3b. Score of ranked reference is allowed to be lower than another properly-ranked codec
Reactions
A. Entire file is thrown out
B. Score of codec with ranked reference is changed to 5.0
C. Score of codec with ranked reference is given the listener rating
Obviously, the most conservative approach is 1a + A
Here's how I might order the choices, from most conservative to less so:
Options Reaction
1a A
1b, 2a, 3a B
1b, 2a, 3a C
1b, 2a, 3b B
1b, 2a, 3b C
1c, 2a, 3a B
1c, 2a, 3a C
1b, 2b, 3a B
1b, 2b, 3a C
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