Want to publicly register predictions or other statements without yet revealing what they say? Do so here. The advantage of commenting here (in addition to, say, your Shortform) is that I'll record all comments here so they can't be deleted or edited later, and I may publicly shame you if you don't reveal your statement when you say you will.

So, comment with

• the date by which (you say) you will reveal your statement, and
• a hash or another system that will provide strong evidence that your statement is what you will say it is.

And, of course, save the statement. (If you use hashing and don't save your exact statement, you of course won't be able to prove it, so not only will your registration be useless, but also it will seem as if you post-facto decided to hide your statement.) If there are some circumstances in which you would not reveal the statement--e.g., if it could be infohazardous--strongly consider

• explaining that in your comment, or
• instead of sharing the hash (or whatever) of your statement, sharing the hash of a message that (1) explains why you might not share your statement and (2) includes or links to the hash of your real statement.

Otherwise, it will look bad if the date arrives and you don't reveal your statement.

To retract or edit a statement, send me a private message within 24 hours of commenting; after that, it cannot be changed in my record (although you can of course comment to say that you no longer endorse it, or to add hashes with new statements).

Fancy methods may exist if you want to provably commit to sharing your statement.

It's your responsibility not to share infohazards. This includes ensuring that any hashes you share can't be reversed, even if computing power advances more than you expect in the time before you reveal your statement, and ensuring that you don't commit to sharing something that, it might turn out, you should not share.

Edit: it seems there are multiple ways to handle verification, but for now, here's the simplest, I think: a sheet with most of the relevant information from comments. Thus information cannot be edited or deleted (without my complicity). And I guess now that there's a sheet, you can PM me rather than comment here to be added if you prefer.