Declaring multiple variable on one line is difficult to read.

Noncompliant Code Example

class MyClass
{
  private int a, b; // Noncompliant

  public void Method()
  {
    int c, d; // Noncompliant
  }
}

Compliant Solution

class MyClass
{
  private int a;
  private int b;

  public void Method()
  {
    int c;
    int d;
  }
}