Don't really know if'n there is a correct "comprehensive" list?
Most all the discounts I've heard of, seen, or used were either posted at the place of business or I asked if they did offer such a discount. Of course there are the "famous ones" such as AAA, AARP, etc.
The post you mentioned in case you want to look at it again was called "Senior Discounts - Do you" started 6/12/14 last post was 7/15/14.
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