yet another example a rocking surface 6712 is exemplified in fig6 and 8 10 rotate or rotatably refers to one or more items mechanisms objects things structures or the like which are capable of being rotated revolved or turned around or about an axis or center spring clip refers to an object item mechanism apparatus combination feature link or the like which is usually made from a deformable material that expands to fit a over a shaft rod arm rail or other structure or b into a hole channel see channel above or the like capable of gripping or holding under spring pressure one common form is a press fit spring clip where the resilient or springy structure as assembled or inserted into a matching hole or channel with a slightly smaller internal dimension through the use of force structural system refers to one or more objects items mechanisms apparatus combinations features link or the like such as rails braces brackets headers feet splices connectors and other connecting devices or structures which may be placed generally between a support structure and a pv module structural system may also include the support structure support or supporting refers to one or more items mechanisms objects things structures or the like which are.