[qqwref]

Here's an idea for a feature similar to what I think TS has.

When you start a song, the server generates and gives you a random "token". Then, when you send a score for that song, you send the token back with it, and the server uses that to validate the score (checks it's the same chart and username, for instance) and marks the token as already used.

Now, with this idea, it would be easy to add a button to send the score again, to help with unrecorded scores. If the score doesn't record, then the token would never be marked as used on the server, so the next time you send the same score it would record normally (and mark the token as used). However, and this is the useful part, if you try to use the button after the score has already properly recorded, the server will notice the token has already been used and refuse to record the score again. So that way we can basically eliminate unrecorded scores, without giving anyone the ability to get credit for the same play more than once.