What is @namespace field in C# class? [duplicate]

Question

I'm browsing the source code of StyleCop, and I found a curious thing:

/// <summary>
/// The namespace that the rule is contained within.
/// </summary>
private string @namespace;

// [...]

internal Rule(string name, string @namespace, string checkId, string context, bool warning) : this(name, @namespace, checkId, context, warning, string.Empty, null, true, false)
{
    Param.Ignore(name, @namespace, checkId, context, warning);
}

What is this thing? Is it just a simple field where at-sign is used to indicate that it is a field, and not a namespace keyword? If so, may at-sign be used for any reserved word (for example @dynamic, @using, etc.)?

Answer 1

Bascially yes. Putting a @ in front of the variable name stops an error ocurring due to that variable name being a keyword.

http://msdn.microsoft.com/en-us/library/x53a06bb(VS.71).aspx

Answer 2

Yes @ sign may be put in front of reserved words to allow them to be used as variable names.

var @dynamic = ...
var @event = ....

I actually learned that, and other things, from this question