What do you call these text bubbles without tails? I saw some radio text bubbles with tails that pointed to the headset, but I am wondering if it's better and more standard to use these tailless radio text bubble. However, I don't understand the rules around them, because on the second panel we see one with a tail, and the other one without a tail. How do we use them? Any rule or suggestion? Also, when writing a script, how do you instruct the artist to put a tailless text bubble instead of one with a tail?
I don't know if this name is standard, but at least one source calls them "jagged edges bubbles."