Family Movie Act Clarification Act of 2018 This bill revises copyright law to permit an individual to make certain changes to a motion picture in a personal capacity. Specifically, the bill allows an individual to make limited portions of a motion picture imperceptible during the individual's private viewing. Additionally, a service that enables these changes to a motion picture is permitted. The bill applies only if no fixed copy of the altered version is created. No motion picture copyright owner may take action to prevent an individual or a service from modifying a motion picture in accordance with this bill. This bill makes conforming amendments to trademark law.