They're concerned about exposing children to (sexually) 'explicit' films.
Changes to the property can't be done without their 'explicit' consent.
The law is very 'explicit' about how these measures should be enacted.
(..) you could shed some light on the subject. We've had that envelope in our possession... ...for the past years. STRANGER: It was given to us with the explicit instructions... ...answering to the name of Marty at this exact location... ...at this exact minute, November , . would actually be here. (..)1989 Back to the Future Part II