20.—(1) Subject to regulation 2 I, where a multi-load is carried—
(a)in separate uncompartmented carrying tanks of a road tanker; or
(b)in separate compartments of a compartmented carrying tank of a road tanker,
the operator of the relevant road tanker shall ensure that each such uncompartmented carrying tank or compartment which contains a dangerous substance is provided with two weather-resistant labels (each indelibly marked on one side only so as to comply with the requirements of Schedule 3) and that those labels are displayed in accordance with paragraph (2).
(2) One of the two labels with which any uncompartmented carrying tank or compartment of a compartmented carrying tank containing a dangerous substance must be provided in accordance with paragraph (1) shall be marked on or securely attached to one side of that carrying tank or compartment or, alternatively, to one side of the frame of the road tanker to which the carrying tank concerned is attached or of which it is an integral part, and the second of those two labels shall be marked on or securely attached to the other side of the said uncompartmented carrying tank or compartment or, as the case may be, frame; and the centre of each such label shall be situated as close as possible to a position midway along the length of the uncompartmented carrying tank or compartment to which it relates.
(3) The driver of any road tanker such as is specified in paragraph (1) shall ensure that the labels with which it is required to be provided in accordance with that paragraph are displayed at all times as required by paragraph (2).
(4) Subject to regulation 21, where a multi-load is carried in separate compartments of a compartmented tank container, the operator of that tank container shall ensure, that each compartment thereof which contains a dangerous substance is provided with two weather-resistant labels (each indelibly marked on one side only so as to comply with the requirements of Schedule 3) and that those labels are displayed on the compartment in accordance with paragraph (5).
(5) One of the two labels with which any compartment of a compartmented tank container containing a dangerous substance must be provided in accordance with paragraph (4) shall be marked on or securely attached to one side of that compartment and the second of those two labels shall be marked on or securely attached to the other side of the said compartment; and the centre of each such label shall be situated as close as possible to a position midway along the length of the compartment to which it relates.
(6) The operator and driver of a vehicle carrying any tank container such as is specified in paragraph (4) shall ensure that the labels with which it is required to be provided in accordance with that paragraph are displayed at all times as required thereby.