Really? Do you know where I can find that information? I have googled but cant find it
King takes king

The rules for blitz are the same as any other time control. The only difference is the time control.

king takes king was the way we all played blitz back a couple decades ago, including the masters, but the accepted convention is now what the others above have stated.
Times change I guess.
You can always play it that way with a friend who agrees with the rule and not feel like some goof making up rules as you go along.
Hi
In Blitz, can my opponent go and capture my king with his king? I know you can do almost anything in Blitz if the opponent doesnt see but taking a king with a king?