http://www.in.gov/legislative/ic/code/const/art11.html
Found number 7 and number 9 most interesting.
Section 7. All bills or notes issued as money shall be, at all times, redeemable in gold or silver; and no law shall be passed, sanctioning, directly or indirectly, the suspension, by any bank or banking company, of specie payments.
Section 9. No bank shall receive, directly or indirectly, a greater rate of interest than shall be allowed, by law, to individuals loaning money.
What I found interesting about 9 is the phrase "to individuals". This implies the individual as the one loaning the money, and the bank collecting interest on said money. Obviously, the goal here with non-endorsement is to NOT allow them to fractionally lend on your money. I'm still digging, in the appendix of Miracle on Main street, I have found a few other interesting things.
1. Lawful money used to be defined in 12 U.S.C. 152, but was repealed in 1994 (The terms 'lawful money' and "lawful money of the United States' shall be construed to mean gold or silver coin of the United States). As well
2. The attorney general from the state as defined in statute cannot render legal opinions to private parties. The question is, what party can they offer opinions too? What is lawful money as defined by this state? I actually know 2 judges...