Screw cap intended to remain attached to a container after opening the container, characterised in that it comprises: - a cylindrical wall having a first longitudinal axis, a first end closed by a bottom and a second end open, the cylindrical wall having an internal surface comprising a thread arranged to cooperate with a thread arranged on a neck of the container, the cylindrical wall being configured to be alternatively in a closed position in which the cylindrical wall is screwed onto the neck and an open position in which the cylindrical wall is unscrewed from the neck and the neck is open, the cylindrical wall comprising a portion forming a tab extending between an attachment tip and a free tip parallel to the first longitudinal axis, the tab having longitudinal edges parallel to the first longitudinal axis, - a security ring extending the cylindrical wall and intended to be retained on the neck by a retaining element arranged on the container, the security ring being connected to the second end of the cylindrical wall by at least one fracturable connection, the fracturable connection being arranged to fracture upon a first unscrewing of the cylindrical wall, - a connecting element connecting the cylindrical wall to the security ring, the connecting element being arranged to allow the cylindrical wall to move along the first longitudinal axis when the cylindrical wall is unscrewed, - an abutment projecting from the tab towards the outside of the cylindrical wall between the free tip and the attachment area of the tab, the tab having a blocking portion between the abutment and the free tip of the tab, the abutment being arranged so that a part of the retaining element is accommodated between the abutment and the blocking portion after a tilting of the tab when the cylindrical wall is brought into a blocking configuration of the cap, the blocking configuration corresponding to a configuration of the open position of the cylindrical wall in which the circular wall is prevented from returning to the closed position, characterized in that the attachment tip of the tab is connected to the cylindrical wall by a hinge and that the connecting element connects an attachment area of the tab to the security ring. - a cylindrical wall having a first longitudinal axis, a first end closed by a bottom and a second end open, the cylindrical wall having an internal surface comprising a thread arranged to cooperate with a thread arranged on a neck of the container, the cylindrical wall being configured to be alternatively in a closed position in which the cylindrical wall is screwed onto the neck and an open position in which the cylindrical wall is unscrewed from the neck and the neck is open, the cylindrical wall comprising a portion forming a tab extending between an attachment tip and a free tip parallel to the first longitudinal axis, the tab having longitudinal edges parallel to the first longitudinal axis, - a security ring extending the cylindrical wall and intended to be retained on the neck by a retaining element arranged on the container, the security ring being connected to the second end of the cylindrical wall by at least one fracturable connection, the fracturable connection being arranged to fracture upon a first unscrewing of the cylindrical wall, - a connecting element connecting the cylindrical wall to the security ring, the connecting element being arranged to allow the cylindrical wall to move along the first longitudinal axis when the cylindrical wall is unscrewed, - an abutment projecting from the tab towards the outside of the cylindrical wall between the free tip and the attachment area of the tab, the tab having a blocking portion between the abutment and the free tip of the tab, the abutment being arranged so that a part of the retaining element is accommodated between the abutment and the blocking portion after a tilting of the tab when the cylindrical wall is brought into a blocking configuration of the cap, the blocking configuration corresponding to a configuration of the open position of the cylindrical wall in which the circular wall is prevented from returning to the closed position, characterized in that the attachment tip of the tab is connected to the cylindrical wall by a hinge and that the connecting element connects an attachment area of the tab to the security ring.