I have some fields in a C# class which I initialize using reflection. The compiler shows CS0649 warning for them:
Field
foo\' is never assigned
If you want to disable ALL warnings in the project (rather than per script) then do this:
Ceate a text file called mcs.rsp (for editor scripts) in your YOUR_PROJECT_NAME/Assets directory with contents (for example):
-nowarn:0649
(You can change the number to match whatever warning you want)
Original answer
Note: This doesn't disable the warnings in the Unity console if you are using Unity (I am still investigating how to remove those)
Here is some Unity documentation with more information