Why is this an issue?

A casez statement has items with integer literals that contain X bits. These bits don't count as wildcards, so the designer may have meant for this to be a casex statement instead.

How to fix it

Code examples

Noncompliant code example

module fly;
  logic [2:0] a;
  initial begin
    casez (a)
      3'b10x:;
    endcase
  end
endmodule

Compliant solution

module fly;
  logic [2:0] a;
  initial begin
    casex (a)
      3'b10x:;
    endcase
  end
endmodule