A filter cartridge 38 includes a first endcap 41 defining a first open aperture and having at least first and second protrusions extending from a wall along the aperture and into the first open aperture. The first protrusion is spaced from the second protrusion in both a vertical direction and a circumferential direction. The filter cartridge also includes filter media 44 and a second endcap 42 . The filter cartridge is mountable in a filter bowl 36 having an inner liner assembly, and the bowl and the inner liner assembly is connectable to a filter head to form a filter system. The filter system can have any one or combination of the following features: a filter lock-out mechanism to ensure that the filter head and the filter bowl are not connectable unless there is a proper filter cartridge installed therein; an automatic drain mechanism to drain the filter bowl of liquid before the filter cartridge is removed from the bowl; and a cartridge retention mechanism, to ensure that the filter cartridge remains with the filter bowl after the filter bowl has been removed from the filter head. Adaptor rings can be utilized in order to test other types of filter elements in the system, when those other types of filter elements do not have the protrusion arrangement. Assemblies, methods of servicing, methods of installing, methods of use, and methods of retaining can be practiced.