Browsing .NET Reference source for some details on [`ClaimsIdentity`](https://referencesource.microsoft.com/#mscorlib/system/security/claims/ClaimsIdentity.cs) class I noticed this:

```
[NonSerialized]
const string PreFix = "System.Security.ClaimsIdentity.";
[NonSerialized]
const string ActorKey = PreFix + "actor"; 

```

What might be a possible reason to use `NonSerializedAttribute` on a `const`?