What is the maximum length of a C#/CLI identifier?

Question

Which other restrictions are there on names (beside the obvious uniqueness within a scope)?

Where are those defined?

Answer 1

From the PDF of ECMA-335, Partition II, section 22:

Metadata preserves name strings, as created by a compiler or code generator, unchanged. Essentially, it treats each string as an opaque blob. In particular, it preserves case. The CLI imposes no limit on the length of names stored in metadata and subsequently processed by the CLI

If I've read this correctly and the context is correct then there's no actual limit to the length of an identifier in the CLR.

Answer 2

In addition to the other answers, the maximum identifier length that is accepted by the Microsoft Visual C# compiler is 511 characters. This can be tested with the following code:

class Program {     private static void Main(string[] args)     {         int aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa = 5;     } } 

The length of the variable name there is 511 characters. This code compiles, but if one character is added to the name, the compiler outputs error CS0645: Identifier too long.