If a phrase adheres to a certain rule, then I call it a Self-cancelling Word™.
Use the examples below to find the rule.
In case you want it in CSV:
Self-cancelling Words™, Not Self-cancelling Words™ WARM, HOT CUSTOMIZE, PERSONALIZE STOPPED, BLOCKED PICTURE, IMAGE FRIGHTENING, SCARY ARRANGEMENT, LAYOUT HIGHWAY, FREEWAY PHOTOGRAPHER, PAPARAZZI NUMEROUS, MANY FAILING, DECLINING BOXING, BATTLING OVER, ACCOMPLISHED
The puzzle relies on the series' inbuilt assumption, that each word can be tested for whether it is a Self-cancelling Word™ or not on its own.
Self-cancelling Words™ are found using a cursive font.