Indication for Reminder Notifications

Hi,

it's great that Observium re-sends alerts every once in a while but I'd love to see a distinction between regular (first-time) alerts and reminder alerts so it is clear on first glance, that this has already been alerted. I cannot suggest a general good way since the length & style depends a lot on the transport mechanism but for emails for example I could imagine a clear "This is a reminder" line with e.g. a red background on the top of the html mail. For others a simply "Reminder: " at the beginning of the text could work.