I created a private key with an Android app I'm no longer using. I had uploaded the public key to the keyservers without setting an expiry date. I later deinstalled that app, and deinstalling apparently deleted the private key, or else I can't find it on my phone.
From time to time, people try to send me an email encrypted in that old key, because they don't know that I don't have access to the private key. Is there any way of revoking the key on the keyserver or adding a comment to prevent people from doing this? (I didn't create a revocation certificate.)