A closing system such as a roller blind, mosquito net, blind, garage door or the like, for equipping an opening defined at the level of a building, this system comprising: - an apron including an end slat; - side guides (3; 3') inside which move the side ends of the apron and/or at least one box inside which is wound and from which unwinds the apron; - a device for limiting the folding of the apron at the end of the travel distance for folding of the apron, this device including; - a support provided with means for receiving the end slat of the apron; - an element movable relative to this support; - a retractable stop, which, at the end of the travel distance for folding of the apron, can occupy, on the one hand and in the absence of an intervention on the limiting device, an active blocking position in which this stop cooperates with a supporting means the opening and/or at least one of the slides (3; 3') and/or the box of the closing system include, for interrupting the folding of the apron and, on the other hand and under the action of an intervention on the limiting device, an inactive blocking position in which this stop is retracted relative to this supporting means, for allowing the continuation of the folding of the apron beyond the end limit position; - means for locking the retractable stop in the active locking position; - means for mounting the movable element slidably relative to the support as well as means for mounting the retractable stop movable relative to the movable element, between the active locking position and the inactive locking position; - wherein the movable element includes the retractable stop, while the means for locking the retractable stop is formed by the support which, through sliding of the movable element relative to the support, can occupy, on the one hand, a locking position of the retractable stop in the active blocking position and, on the other hand, an unlocking position of the retractable stop. - an apron including an end slat; - side guides (3; 3') inside which move the side ends of the apron and/or at least one box inside which is wound and from which unwinds the apron; - a device for limiting the folding of the apron at the end of the travel distance for folding of the apron, this device including; - a support provided with means for receiving the end slat of the apron; - an element movable relative to this support; - a retractable stop, which, at the end of the travel distance for folding of the apron, can occupy, on the one hand and in the absence of an intervention on the limiting device, an active blocking position in which this stop cooperates with a supporting means the opening and/or at least one of the slides (3; 3') and/or the box of the closing system include, for interrupting the folding of the apron and, on the other hand and under the action of an intervention on the limiting device, an inactive blocking position in which this stop is retracted relative to this supporting means, for allowing the continuation of the folding of the apron beyond the end limit position; - means for locking the retractable stop in the active locking position; - means for mounting the movable element slidably relative to the support as well as means for mounting the retractable stop movable relative to the movable element, between the active locking position and the inactive locking position; - wherein the movable element includes the retractable stop, while the means for locking the retractable stop is formed by the support which, through sliding of the movable element relative to the support, can occupy, on the one hand, a locking position of the retractable stop in the active blocking position and, on the other hand, an unlocking position of the retractable stop. - an element movable relative to this support; - a retractable stop, which, at the end of the travel distance for folding of the apron, can occupy, on the one hand and in the absence of an intervention on the limiting device, an active blocking position in which this stop cooperates with a supporting means the opening and/or at least one of the slides (3; 3') and/or the box of the closing system include, for interrupting the folding of the apron and, on the other hand and under the action of an intervention on the limiting device, an inactive blocking position in which this stop is retracted relative to this supporting means, for allowing the continuation of the folding of the apron beyond the end limit position; - means for locking the retractable stop in the active locking position; - means for mounting the movable element slidably relative to the support as well as means for mounting the retractable stop movable relative to the movable element, between the active locking position and the inactive locking position; - wherein the movable element includes the retractable stop, while the means for locking the retractable stop is formed by the support which, through sliding of the movable element relative to the support, can occupy, on the one hand, a locking position of the retractable stop in the active blocking position and, on the other hand, an unlocking position of the retractable stop.