nina@ suggested that the following message could be used when sending someone a dare via the RandomDarer. Thank you nina@!
So if you get a dare from someone through The RandomDarer which is not yet in the following style, I'd like to suggest to you to use this message instead, with "You've been dared by The RandomDarer!" in the title.
YOU'VE BEEN DARED!! 
Your dare: <dare code>
Click the following link (only once) to see who the next victims are 
<link>
Send them a pm dare and the link above to continue the chain.