MGN 533 (M) Means of Access (link)
This Marine Guidance Note gives guidance on the measures that shipowners and employers are expected to take in order to provide a safe means of access on UK ships.
In order to ensure the safety of those leaving or joining the ship, a safe means of access is required between the ship and any quay, pontoon, other structure, or another ship alongside which the ship is secured. The master is responsible for ensuring that a safe means of access is provided, even if the equipment is provided from the shore-side.
Source: MCA