diff --git a/NEWS b/NEWS
index 1d6cf3c2f..4c992b513 100644
--- a/NEWS
+++ b/NEWS
@@ -12,6 +12,15 @@ VERSION next
 
 troff
 -----
+o GNU troff now issues an error diagnostic when the 'f' drawing command
+  is used (in a `\D'f 500'` escape sequence, for example).  This drawing
+  command was declared obsolete in this NEWS file 20 years ago as part
+  of the groff 1.19 release.  Users of this escape sequence will want to
+  migrate to the `Fg` drawing command or use higher level language
+  features, like the `defcolor` and `fcolor` requests, and the `\M`
+  escape sequence, for setting a grayscale fill color for geometric
+  objects.  Support for 'f' may disappear in the next release.
+
 o GNU troff output now reports unbreakable spaces (those produced with
   the `\~` escape sequence) as word breaks with the documentary 'w'
   command, just as regular breakable spaces do.
@@ -58,6 +67,17 @@ o The s (ms) macro package now sets the vertical spacing register
   document with a type size of 20 points, the vertical spacing now
   defaults to 24 points rather than 22.
 
+Output drivers
+--------------
+
+o Output drivers now issue a warning diagnostic when the 'f' drawing
+  command is used (`Df 500 0`, for example).  This drawing
+  command was declared obsolete in this NEWS file 20 years ago as part
+  of the groff 1.19 release.  Users of this escape sequence will want to
+  migrate to the `Fg` drawing command to set a grayscale fill color for
+  geometric objects.  Support for 'f' may disappear in the next release,
+  producing an error diagnostic regarding an unrecognized command.
+
 
 VERSION 1.23.0
 ==============
diff --git a/src/devices/gropdf/gropdf.pl b/src/devices/gropdf/gropdf.pl
index e86644da5..2067f0a19 100644
--- a/src/devices/gropdf/gropdf.pl
+++ b/src/devices/gropdf/gropdf.pl
@@ -3140,6 +3140,7 @@ sub do_D
     }
     elsif ($Dcmd eq 'f')
     {
+	Warn("'f' drawing command is obsolete; use 'Fg' instead");
 	my $mcmd=substr($par,0,1);
 
 	$par=substr($par,1);
diff --git a/src/libs/libdriver/input.cpp b/src/libs/libdriver/input.cpp
index 821b526bd..78f73379a 100644
--- a/src/libs/libdriver/input.cpp
+++ b/src/libs/libdriver/input.cpp
@@ -1361,6 +1361,7 @@ parse_D_command()
     }
   case 'f':			// Df: set fill gray; obsoleted by DFg
     {
+      warning("'f' drawing command is obsolete; use 'Fg' instead");
       IntArg arg = get_integer_arg();
       if ((arg >= 0) && (arg <= 1000)) {
 	// convert arg and treat it like DFg
diff --git a/src/roff/troff/input.cpp b/src/roff/troff/input.cpp
index e797e2200..cc0b59f38 100644
--- a/src/roff/troff/input.cpp
+++ b/src/roff/troff/input.cpp
@@ -8754,6 +8754,9 @@ static node *read_draw_node()
 	    error("even number of arguments needed for spline");
 	  break;
 	case 'f':
+	  error("'f' drawing command is obsolete;"
+		" use 'Fg' drawing command, 'M' escape sequence,"
+		" or 'fcolor' request instead");
 	  if (npoints != 1 || !no_last_v) {
 	    error("one argument needed for gray shade");
 	    npoints = 1;