Right now, no comment fields. I do not typically punish for small spelling mistakes if you still get the meaning of the mnemonic.
As for feedback to the user, I am split on this, but I'm forming something out in my heads. Concerns (and benefits)
1. If the usage note validation system is too cumbersome, might drive down participation
2. If a note is rejected, there are two reasons: either it's just not right for renshuu, or it could be right if small changes were made. I'm not sure the first one needs to be sent to them. As for the second, perhaps if it was something like this "it was rejected, and at least x people marked the same reason (it would have to be a dropdown, and not a text field), then send them a "we think your note has potential, but please consider making this change: ________"
I most likely won't have much time to do more on this due to the holidays, but I'd like to give you the initial stats I've gotten.
So far, 70 notes have been marked by 5 or more people.
Given a threshold of 2/3s (66.6%):
1. 40 of them would be accepted ( # of accepted / (# of accepted + # of unaccepted) > .66)
2. Only 21 of those would be accepted, though, if it requires .66 of total votes INCLUDING "not sure".
3. 20 would be rejected (when not considering "not sures"), but only 6 would (when including not sure).
The average "not sure" rate was 30% across all 70 notes.
To put this another way, if we remove unsures from the percentages, 61 of the 70 have a 66.6% majority in one direction or the other. If we include them, though, that drops to 27, meaning that 34 (roughly 50%) of them have enough people saying "huh" that it needs me to check on the notes, at least until the system is more mature and we have a trust system built in to weight the votes of other users.