What is the difference between warning codes cs0618 and cs0612

Question

I have seen both of the following warning codes being thrown for utilization of code marked obsolete.

cs0618 and cs0612.

0618 is Level 2 and 0612 is level

Answer 1

I think the difference is that one contains a message and the other doesn't.

[Obsolete]                                  // CS0612
[Obsolete("Use newMethod instead", false)]  // CS0618
[Obsolete("Use newMethod instead", true)]   // CS0619