What are the requirements when choosing an identifier for a C# class?

What will be an ideal response?

You can define a C# class using any identifier you need, as long as it meets the following requirements:
* An identifier must begin with an underscore, the "at" sign (@), or a letter. (Letters include foreign-alphabet letters, which are contained in the set of characters known as Unicode.)
* An identifier can contain only letters, digits, underscores, and the "at" sign (@). It cannot contain spaces or any other punctuation or special characters such as #, $, or &.
* An identifier cannot be a C# reserved keyword, such as class or void. (Actually, you can use a keyword as an identifier if you precede it with an "at" sign, as in @class. An identifier with an @ prefix is a verbatim identifier. This feature allows you to use code written in other languages that do not have the same set of reserved keywords. However, when you write original C# programs, you should not use the keywords as identifiers.)