A rail for use as a movable rail in an architectural covering, wherein: the rail includes a first end and extends in a first direction from the first end; the rail includes a cord guiding insert for mounting at the first end; at the first end, the rail has a cross-section with an inner profile shape defining an entrance into the rail; the rail defines an inner space extending in the first direction from said entrance and for receiving a cord; the cord guiding insert includes a base with an outer surface and an inner surface opposite to the outer surface, and includes at least one insert portion extending from the inner surface; the at least one insert portion has an outer shape matching at least part of the inner profile shape of the first end; the cord guiding insert is configured to be mounted at the first end with said at least one insert portion inserted into said entrance with the outer shape of the at least one insert portion fitting with said at least part of the inner profile shape to engage the cord guiding insert to the first end; characterised in that: the cord guiding insert is configured to be mounted at the first end with the base partially closing said entrance to define a cord opening between a first side of the base and the inner profile shape; and the outer surface of the base defines a channel extending from the first side of the base to an opposite second side of the base whereby, with the cord guiding insert engaged to the first end, said cord may be guided out of the inner space, through the cord opening and along the channel defined by the outer surface of the base. the rail includes a first end and extends in a first direction from the first end; the rail includes a cord guiding insert for mounting at the first end; at the first end, the rail has a cross-section with an inner profile shape defining an entrance into the rail; the rail defines an inner space extending in the first direction from said entrance and for receiving a cord; the cord guiding insert includes a base with an outer surface and an inner surface opposite to the outer surface, and includes at least one insert portion extending from the inner surface; the at least one insert portion has an outer shape matching at least part of the inner profile shape of the first end; the cord guiding insert is configured to be mounted at the first end with said at least one insert portion inserted into said entrance with the outer shape of the at least one insert portion fitting with said at least part of the inner profile shape to engage the cord guiding insert to the first end; characterised in that: the cord guiding insert is configured to be mounted at the first end with the base partially closing said entrance to define a cord opening between a first side of the base and the inner profile shape; and the outer surface of the base defines a channel extending from the first side of the base to an opposite second side of the base whereby, with the cord guiding insert engaged to the first end, said cord may be guided out of the inner space, through the cord opening and along the channel defined by the outer surface of the base. the cord guiding insert is configured to be mounted at the first end with the base partially closing said entrance to define a cord opening between a first side of the base and the inner profile shape; and the outer surface of the base defines a channel extending from the first side of the base to an opposite second side of the base whereby, with the cord guiding insert engaged to the first end, said cord may be guided out of the inner space, through the cord opening and along the channel defined by the outer surface of the base.