diff --git a/C#-and-.NET-docs-supplement.md b/C#-and-.NET-docs-supplement.md
index c7ccc8f..db8b33b 100644
--- a/C#-and-.NET-docs-supplement.md
+++ b/C#-and-.NET-docs-supplement.md
@@ -17,6 +17,9 @@ On (older versions of?) VS, `Condition` is ignored if placed on a property. Crea
 
 ## MSBuild property evaluation execution order
 
+<!-- TODO check
+When `<Import/>`ing a `.props` file, `ProjectDir` is unset during property evaluation i.e. in `<PropertyGroup/>`s (but `SolutionDir` *is* set, if applicable). Use `MSBuildProjectDirectory`.
+-->
 When `<Import/>`ing a `.props` file, `ProjectDir` is unset (but `SolutionDir` *is* set, if applicable). Use `MSBuildProjectDirectory`.
 
 ## `String.GetHashCode` stability