does it mean that the laser is originally 30mW and they didn't make it higher by pot modding it? and if a laser on a website is just '30mW' does that mean it was a 5 or 10mW and they pot modded it to a 30?
It's a marketing term, it doesn't really "mean" anything. It's supposed to make you believe that their "50 mW" lasers are somehow better then someone else's "50 mW" lasers. I would be more concerned with the actual testing methodology (duration, equipment and method) than with a single word in the product description. Anyone can say their laser is "true 50mW" but if they are only testing it for 20 seconds on an antique calorimeter then it's not worth squat. Always ask the seller HOW they test their lasers, not just IF they test them.