can have corrugations 34 formed therein so as to lend additional thickness and strength to the flange another tongue flange 36 can be provided substantially opposite the tongue flange 30 the tongue flange 36 can be raised from an opposite side of the base portion 24 by a leg flange 40 the tongue flange 36 can also include corrugations 34 for additional thickness and strength the system of the invention can be used to trim a door and to install a door jamb without a need for tapered wood shims a clip according to the invention would preferably include a center spacing portion 42 extending from the base portion 24 the center spacing portion 42 can be substantially planar and has door jamb engagement structure at an end distal to the base portion 24 the door jamb engagement structure preferably is a flange 46 that is substantially perpendicular to the center spacing portion depending oppositely from the raised tongue flanges 30 and 36 and is adapted to engage a bore in the door jamb the door jamb engagement flange preferably has saw tooth projections 50 to firmly engage the door jamb additional structure for engaging the clip to a door jamb can be provided an aperture 52 can be provided in the center spacing portion 42 and is adapted to receive suitable fastening structure such as a screw to firmly secure the clip.