Question

Looking at System.Windows.Threading.Dispatcher (as decompiled by Reflector) I came across;

[field: SecurityCritical]
public event DispatcherUnhandledExceptionFilterEventHandler UnhandledExceptionFilter;

I don’t recognize the ‘field’ part of the attribute declaration, what is it?

Edit:

This is how it appears in the reference source:

    public event DispatcherUnhandledExceptionFilterEventHandler UnhandledExceptionFilter
    { 
        [SecurityCritical] 
        [UIPermissionAttribute(SecurityAction.LinkDemand,Unrestricted=true)]
        add 
        {
            _unhandledExceptionFilter += value;
        }
        [SecurityCritical] 
        [UIPermissionAttribute(SecurityAction.LinkDemand,Unrestricted=true)]
        remove 
        { 
            _unhandledExceptionFilter -= value;
        } 
    }

Answer 1

field: is called an attribute target. It lets you specify the target (assembly, return, etc.) for the attribute.

See http://msdn.microsoft.com/en-us/library/b3787ac0.aspx for more details.