diff --git a/C#-and-.NET-docs-supplement.md b/C#-and-.NET-docs-supplement.md
index f922dda..c8edfde 100644
--- a/C#-and-.NET-docs-supplement.md
+++ b/C#-and-.NET-docs-supplement.md
@@ -30,6 +30,8 @@ When `<Import/>`ing a `.props` file, `ProjectDir` is unset (but `SolutionDir` *i
 
 The `GetHashCode` implementation for strings does not reflect the string's contents, and as such, the hash not stable between program instances.
 
+It seems that `Guid`'s implementation *is* stable across instances, and even across Mono and .NET 6+ implementations. It also gives `0` for `Guid.Empty` which is nice.
+
 ## `System.Drawing.SystemIcons` rendered
 
 [Docs for `SystemIcons`](https://learn.microsoft.com/en-us/dotnet/api/system.drawing.systemicons?view=netframework-4.8) don't include any pictures, so here they are (Win10, Mono 6.12.x):