diff --git a/StackXML/XmlWriteBuffer.cs b/StackXML/XmlWriteBuffer.cs
index 8da4777..2c550aa 100644
--- a/StackXML/XmlWriteBuffer.cs
+++ b/StackXML/XmlWriteBuffer.cs
@@ -128,7 +128,7 @@ public void PutAttribute<T>(ReadOnlySpan<char> name, T value) where T : ISpanFor
 
         public void PutAttribute(ReadOnlySpan<char> name, bool value)
         {
-            // todo: why is bool not ISpanFormattable?
+            // todo: why is bool not ISpanFormattable? See https://github.com/dotnet/runtime/issues/67388.
             PutAttribute(name, value ? '1' : '0');
         }
 
@@ -288,4 +288,4 @@ public void EncodeText(ReadOnlySpan<char> input, bool attribute=false)
             }
         }
     }
-}
\ No newline at end of file
+}