What constitutes "proof of time"? Is there a form or something I have to fill out? How do I know if a race is "certified" and certified by who? I found a local 10k I can do in October to have something for the Marathon Weekend Half. I'm certainly not expecting to be leading any packs, but I have read trip reports of people stuck in the last corral taking 24 minutes to do the first mile because of all the walkers. Also, if I am running with my sister, is there a way to be sure we are in the same corral? Thanks!