Ok, just have to pull you up a bit here - i don't know if this was a willful misreading, or inadvertant, but this is not what i wrote or meant.
If something is an "illegal method" it is not grey, it's black. Illegal methods are in the WADA documentation.
What are being discussed is not methods that are illegal by reason of meating a category description in the WADA code but not explicitly named. We are talking about things that ARE currently legal, but ETHICALLY dubious - i.e. INSIDE the LETTER of the rules, but arguably not inside the spirit. Legal painkillers being overused to dull exertion pain, rather than treat injury meets this description to a tee.
Perhaps it would be best to highlight "grey area" could have two meanings in this context.
1. Legally dubious or unclear.
2. Ethically dubious or unclear.
Tramadol seems to fit 2, unless someone can advise me otherwise.