A dovetail rail or dovetail mount can refer to several types of sliding rail system found on firearms primarily for mounting telescopic sights. Colloquially, the term dovetail rail usually refer to any straight mounting bracket with an inverted trapezoid (dovetail) cross-section (though the hexagonal-profiled Weaver rail and Picatinny rail are also derivative dovetail designs) running parallel to the bore for mounting a scope or diopter sight to a rifle. These are sometimes also called "tip-off" mounts, and allow the user to easily take on or off the sight. Dovetail mount can also refer to a dovetail track running perpendicular to the bore (see "Other uses" below).