diff --git a/development/FORMAT b/development/FORMAT
index 56cd4369f5..8adbb250a1 100644
--- a/development/FORMAT
+++ b/development/FORMAT
@@ -20,6 +20,9 @@ changes happened in particular if possible. A good example would be
 	* Format incremented to 616: Do not output LaTeX for a macro if the LaTeX part is empty
 	- This allows the user to define the LyX display for LaTeX commands
 	  that are already defined (e.g., in user preamble or a package).
+	- No substantive change to file format. Format change just in case someone defined a
+	  math macro with an empty LaTeX field. In that case, lyx2lyx adds {} to the LaTeX 
+	  part on conversion and removes the macro altogether on reversion.
 
 2023-04-02 Jürgen Spitzmüller <spitz@lyx.org> 
 	* Format incremented to 615: Unifiy spelling of "acknowledgment" styles