existing wall surface), to provide an even surface for installing vinyl siding. Buttlock -- the bottom edge of a siding or soffit panel, or accessory piece, opposite the nailing slots, which locks onto to the preceding panel. Channel -- the area of the accessory trim or corner post where siding or soffit panels are inserted. Channels also refer to the trim itself, and are named for the letters of the alphabet they resemble (e.g., J-channel, F-channel, etc.). Course -- a row of panels, one panel wide, running the length of the house from one side to the other, or, in the case of vertical siding, from top to bottom. H-Channel -- a siding accessory that joins two soffit panels, or used as transition between two siding sections. Face -- refers to the side of a siding or soffit panel that is showing once the panel has been installed. Face-Nailing -- the action of fastening directly onto the "face" side of a panel (instead of using the nail hem slot). This practice is generally not used in siding installation. Fascia -- the trim covering the ends of roof rafters and gables. Fascia Board -- a board attached to the ends of the rafters and gables between the roofing material and the soffit overhang. Fascia cap is the covering around that board. Flashing -- a thin, flat material, usually aluminum, positioned under or behind J-channels, corner posts, windows, etc., to keep draining water from penetrating the home. Flashing is also used around