This is a number that's returned as an exit code in many .NET exceptions (particularly COM exceptions, I think).
In this question someone used Reflector to find out that this value was initialized to a private variable in nearly every Exception constructor.
My question is, why? What significance does this number have? It's hard to believe that it was chosen arbitrarily. I don't even see any numeric significance (e.g., in its binary or hex representation).
Did you pay attention to its hex representation, E0434F4D? Here's a brief synopsis:
E0 - represents E 43 - ASCII for C 4F - ASCII for O 4D - ASCII for M
So it's ECOM, or "exception from COM".
来源：https://stackoverflow.com/questions/9164050/whats-the-significance-of-532459699