Cylinder of pressurised fluid provided with a tap housing a first bleed-off circuit comprising a first upstream end communicating with the storage volume of a cylinder of pressurised fluid and a second downstream end configured to be connected to a member using the bleed-off gas, the first bleed-off circuit comprising a flow and/or pressure regulation member for the bleed-off fluid between the upstream and downstream ends, the tap comprising a member for manual control of the regulation member, the control member being mounted movable with respect to the body of the tap and cooperating with the regulation member to control the flow and/or the pressure of the fluid allowed to flow from the upstream end to the downstream end according to the position of the control member with respect to the body, the tap comprising an electronic device indicating the data relating to the content of fluid in a cylinder connected to the tap, the electronic indicator device comprising a member for the acquisition, storage and processing of data and at least one data display connected to the member for the acquisition, storage and processing of the data, the tap comprising a sensor for the position of the member for manual control of the regulation member, the position sensor being connected to the member for the acquisition, storage and processing of data to transmit to the latter a signal representing the flow and/or pressure of the fluid imposed by the regulation member, the member for the acquisition, storage and processing of data being configured to demand the displaying on the display, after filling of the cylinder and before a first bleed-off of the fluid, of fixed information relating to a determined fixed content of fluid in the cylinder, as long as the position sensor has not transmitted a signal representing a non-nil flow and/or pressure of the bleed-off fluid for a determined period and/or has not transmitted a signal representing a determined quantity of bleed-off fluid, the manual demand member of the regulation member being movable into a so-called "closed" position corresponding to a closure of the first bleed-off circuit, i.e. that the flow of fluid allowed to pass from the upstream end to the downstream end is nil, characterised in that the tap comprises a pressure sensor configured to measure the pressure within the storage volume of the cylinder, the sensor being connected to the member for the acquisition, storage and processing of the data to transmit to the latter, in a wired and/or wireless manner, a signal representing the measured fluid pressure, and in that the tap comprises a second bleed-off circuit bypassing the flow and/or pressure regulation member of the first bleed-off circuit, and in that, when the manual control member is in its closed position and the variation of the signal representing the pressure of the fluid within the cylinder is greater that a given variation threshold, the member for the acquisition, storage and processing of data is configured to detect a fluid bleed-off through the second bleed-off circuit or a fluid leakage and, as necessary, to demand the display on the display of information relating to a bleed-off through the second bleed-off circuit and/or relating to a leakage.