A lift cord system for operating a retractable covering for architectural openings includes at least one cord loop which extends from a tassel through a fabric for the covering where it is slidably connected to the bottom rail for adjustment of the desired maximum spacing of the top rail and bottom rail and the orientation of the bottom rail relative to the top rail so the rails can be easily maintained in a parallel relationship. The cord loop is also anchored to the bottom rail at a separate location in a manner so as to fix the maximum separation between the top and bottom rails so the covering desirably fits the size of the architectural opening in which it is mounted. alternative embodiments include top down/bottom up coverings and coverings including a middle rail in addition to top and bottom rails.