Maybe I'm just unlucky, but I go to WDW several times a year and it seems like at least once a trip, some restaurant can't find my ADR using just my name.

I frequently use the DxDDP, so have alot of ADRs each trip though. I always have my ADR confirmation numbers handy.
I write very small anyway, so what I do is write them on a couple of the Home Depot's lime green Mickey heads, cut them out, glue them together, laminate them, punch a hole in one of the ears, insert one of those rubber luggage tag thingy's, then loop it onto my park bag. That way my ADRs are always handy and anyone can identify me as a DISer. If I'm on the basic
DDP, I write them on one Mickey head, then just write my DIS screen name on the other, and do them the say way. I use initials so they look like this:
9/4 12N GG 123456789
7:20pm CG 234567890
9/5 8am CRT 098765432
1pm LTT 234998654
7:30pm 50's PT 234999999
9/6 8am TH 456789123
1pm Y&Y 567890123