Almost every new watch I've ever seen has some sort of covering or coating on the caseback; for example, on my recently-acquired Pulsar there is a blue static-cling-like piece of plastic that covers all the writing on the caseback, including the serial number.
Are these supposed to be removed before wearing the watch? I'm assuming they are designed only to protect the writings until the watch is purchased. I have always removed them out of concern that heat, sweat, and other elements would turn them into a nasty mess that either stains the watch or stains my wrist.
Is there any reason for keeping these coverings/coatings intact on the caseback?