A closing cap for a container, comprising a lateral wall extending around an axis and a transversal wall positioned at one end of the lateral wall, a separation line being provided on the lateral wall to define: a retaining ring, which is configured to remain anchored to a neck of the container; a closing element removably engageable with the neck, so as to open or close the container; the separation line extending around the axis and being circumferentially interrupted to leave the retaining ring and the closing element joined; wherein the retaining ring comprises: - a retaining portion, which is configured to internally engage with a locking ring of the neck and extends as far as a free edge of the retaining ring; - a joining portion where the retaining ring is joined to the closing element; - a first connecting band, which extends from a first end zone of the joining portion to the retaining portion, and a second connecting band, which extends from a second end zone of the joining portion to the retaining portion, the second end zone being positioned circumferentially on the opposite side to the first end zone; - a tab, interposed between the first connecting band and the second connecting band, the tab projecting relative to the first end zone and relative to the second end zone towards the free edge so that, when the closing element is in an open condition and the connecting bands (306, 307) keep the closing element connected to the retaining ring, the tab can rest on the neck; characterized in that the connecting bands (306; 307) and the tab are made by means of an incision line which extends between the separation line and the free edge of the retaining ring, wherein the incision line comprises a central stretch which is interposed between a first lateral stretch and a second lateral stretch of the incision line, wherein the incision line is made by incisions passing through an entire thickness of the lateral wall. a retaining ring, which is configured to remain anchored to a neck of the container; a closing element removably engageable with the neck, so as to open or close the container; the separation line extending around the axis and being circumferentially interrupted to leave the retaining ring and the closing element joined; wherein the retaining ring comprises: - a retaining portion, which is configured to internally engage with a locking ring of the neck and extends as far as a free edge of the retaining ring; - a joining portion where the retaining ring is joined to the closing element; - a first connecting band, which extends from a first end zone of the joining portion to the retaining portion, and a second connecting band, which extends from a second end zone of the joining portion to the retaining portion, the second end zone being positioned circumferentially on the opposite side to the first end zone; - a tab, interposed between the first connecting band and the second connecting band, the tab projecting relative to the first end zone and relative to the second end zone towards the free edge so that, when the closing element is in an open condition and the connecting bands (306, 307) keep the closing element connected to the retaining ring, the tab can rest on the neck; characterized in that the connecting bands (306; 307) and the tab are made by means of an incision line which extends between the separation line and the free edge of the retaining ring, wherein the incision line comprises a central stretch which is interposed between a first lateral stretch and a second lateral stretch of the incision line, wherein the incision line is made by incisions passing through an entire thickness of the lateral wall. - a retaining portion, which is configured to internally engage with a locking ring of the neck and extends as far as a free edge of the retaining ring; - a joining portion where the retaining ring is joined to the closing element; - a first connecting band, which extends from a first end zone of the joining portion to the retaining portion, and a second connecting band, which extends from a second end zone of the joining portion to the retaining portion, the second end zone being positioned circumferentially on the opposite side to the first end zone; - a tab, interposed between the first connecting band and the second connecting band, the tab projecting relative to the first end zone and relative to the second end zone towards the free edge so that, when the closing element is in an open condition and the connecting bands (306, 307) keep the closing element connected to the retaining ring, the tab can rest on the neck; characterized in that the connecting bands (306; 307) and the tab are made by means of an incision line which extends between the separation line and the free edge of the retaining ring, wherein the incision line comprises a central stretch which is interposed between a first lateral stretch and a second lateral stretch of the incision line, wherein the incision line is made by incisions passing through an entire thickness of the lateral wall.