Why is this an issue?

A wildcard case statement contains overlapping items, which can be confusing since the overlapping value(s) will only ever match the first item in the list.

How to fix it

Code examples

Noncompliant code example

module fly;
  logic [3:0] a;
  initial begin
    casez (a)
      4'b1011:;
      4'b101?:;
      default;
    endcase
  end
endmodule

Compliant solution

module fly;
  logic [3:0] a;
  initial begin
    casez (a)
      4'b1011:;
      4'b111?:;
      default;
    endcase
  end
endmodule