diff --git a/doc/README.Converters.md b/doc/README.Converters.md
index 876f17433..1069720b9 100644
--- a/doc/README.Converters.md
+++ b/doc/README.Converters.md
@@ -177,6 +177,12 @@ above.
 
 `drawio -x -f pdf -o "%o" "%f"`
 
+### troff files
+
+`groff -pet -ms -Tpdf "%f" > "%o"`
+
+`pdfroff "%f" > "%o"`
+
 ## Conversion to png for preview images
 
 If you have problems running convert on PDF documents then read the page