Level 1/3: Structural Verilog : Structural, Heirarchic, Netlist
BEGIN subcircuit(clk, rst, q2);
INPUT clk, rst;
OUTPUT q2;
Ff1 : DFFR(clk, rst, a, q1, qb1);
Ff2 : DFFR(clk, rst, q1, q2, qb2);
Ff3 : DFFR(clk, rst, q2, q3, qb3);
Nor : NOR2(a, q2, q3);
END subcircuit;
Just a netlist.
There are no assignment statements that transfer data between registers in structural RTL (but it's still a form or RTL).