Variable can be made constant.

Why is this an issue ?

Unlike variables, constant values are known at compile time and are injected as is in the code, requiring no runtime processing and therefore reducing the environmental footprint. Although good compilers will const eligible variables by themselves, it is still good practice to declare them constant, as it makes the code intent clearer.

When can it be ignored ?

This rule should not be ignored.

Non compliant examples

public void Main()
{
    int i = 0; // Non compliant, i is never reassigned and can be made constant
    Console.WriteLine(i);
}

Compliant examples

public void Main()
{
    const int i = 0; // Compliant, i is declared as constant
    Console.WriteLine(i);
}

public void Main()
{
    int i = 0; // Compliant, i is reassigned in the next line
    Console.WriteLine(i++);
}