Visual Studio: GlobalSuppressions.cs: Prefix ~P: for attribute Target in SuppressMessage

Question

I suppressed several (IntelliSense) messages in Visual Studio 2017. I created entries in file GlobalSuppressions.cs like:

[assembly: System.Diagnostics.CodeAnalysis.SuppressMessage("Wrong Usage", "DisposableFixer:Undisposed ressource.", Justification = "<Pending>", Scope = "member", Target = "~M:MyProg.Class1.....Method1")]

[assembly: System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "CC0001:You should use 'var' whenever possible.", Justification = "<Pending>", Scope = "member", Target = "~P:MyProg.Class2.Setter1")]

The prefixes ~M: and ~P: in attribute Target seem to be some kind of filter. What do they mean? The only document I find about Target, is: "It must contain a fully-qualified item name."

Answer 1

I finally found the documentation I was looking for. It reads:

The first part of the string identifies the kind of member being documented, via a single character followed by a colon. The following kinds of members are defined:

Character	Description
E	Event
M	Method (including constructors, destructors, and operators)
N	Namespace
P	Property (including indexers)
T	Type (such as class, delegate, enum, interface, and struct)
!	Error string; the rest of the string provides information about the error. For example, the documentation generator generates error information for links that cannot be resolved.

I guess the first and the last entries are not relevant for suppression messages and the leading ~ is fixed by convention.

So, for example, to suppress all warnings of a given type in a whole namespace, you write:

[assembly: System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "CC0001:You should use 'var' whenever possible.", Scope = "namespaceanddescendants", Target = "~P:MyProg.Class2.Setter1")]

BTW, the allowed values for Scope are described here:

Value	Description
"member"	Suppresses warnings against a member.
"module"	Suppresses warnings against an assembly. It is a global suppression that applies to the entire project.
"namespace"	This scope suppresses warnings against the namespace itself. It does not suppress warnings against types within the namespace.
"namespaceanddescendants"	Suppresses warnings in a namespace and all its descendant symbols. This value is ignored by legacy code analysis.
"type"	Suppresses warnings against a type.