Code PxBN(M):

P = Type of tank:

Tank, battery-vehicle or MEGC for liquefied gases or dissolved gases.
-------------------------

x = Calculation pressure:

Value of the minimum relevant test pressure according to the table in 4.3.3.2.5.
-------------------------

B = Openings (see 6.8.2.2 and 6.8.3.2):

Tank with bottom filling or discharge openings with 3 closures; or battery-vehicle or MEGC with openings below the surface of the liquid or for compressed gases.
-------------------------

N = Safety valves/devices:

Tank, battery-vehicle or MEGC with safety valve according to 6.8.3.2.9 or 6.8.3.2.10 which is not hermetically closed.
-------------------------

(M) = The substance can also be carried in battery-vehicles or MEGCs.