Because the value in a variable of an unsigned type can never be less than zero, testing to see if it is negative is a useless operation which can
only confuse future readers of the code.
Noncompliant code example
unsigned int i = 0; // the lowest value this var can have
...
if (i >= 0) { // Noncompliant
do_x(i);
}
Compliant solution
unsigned int i = 0;
...
do_x(i);
