diff --git a/runtime/doc/syntax.txt b/runtime/doc/syntax.txt
index 686c98a..ff9be2e 100644
--- a/runtime/doc/syntax.txt
+++ b/runtime/doc/syntax.txt
@@ -4901,6 +4901,10 @@
 
 ctermfg={color-nr}				*highlight-ctermfg* *E421*
 ctermbg={color-nr}				*highlight-ctermbg*
+ctermul={color-nr}				*highlight-ctermul*
+	These give the foreground (ctermfg), background (ctermbg) and
+	underline (ctermul) color to use in the terminal.
+
 	The {color-nr} argument is a color number.  Its range is zero to
 	(not including) the number given by the termcap entry "Co".
 	The actual color with this number depends on the type of terminal
@@ -4978,11 +4982,11 @@
 	needs to reset the color when exiting.	This is done with the "op"
 	termcap entry |t_op|.  If this doesn't work correctly, try setting the
 	't_op' option in your .vimrc.
-							*E419* *E420*
-	When Vim knows the normal foreground and background colors, "fg" and
-	"bg" can be used as color names.  This only works after setting the
-	colors for the Normal group and for the MS-Windows console.  Example,
-	for reverse video: >
+							*E419* *E420* *E453*
+	When Vim knows the normal foreground, background and underline colors,
+	"fg", "bg" and "ul" can be used as color names.  This only works after
+	setting the colors for the Normal group and for the MS-Windows
+	console.  Example, for reverse video: >
 	    :highlight Visual ctermfg=bg ctermbg=fg
 <	Note that the colors are used that are valid at the moment this
 	command are given.  If the Normal group colors are changed later, the
diff --git a/runtime/doc/term.txt b/runtime/doc/term.txt
index 9e0b0bb..87e5624 100644
--- a/runtime/doc/term.txt
+++ b/runtime/doc/term.txt
@@ -322,6 +322,7 @@
 	t_ZR	italics end					*t_ZR* *'t_ZR'*
 
 Added by Vim (there are no standard codes for these):
+	t_AU	set underline color (ANSI)			*t_AU* *'t_AU'*
 	t_Ce	undercurl end					*t_Ce* *'t_Ce'*
 	t_Cs	undercurl mode					*t_Cs* *'t_Cs'*
 	t_Te	strikethrough end				*t_Te* *'t_Te'*
@@ -350,6 +351,7 @@
 		|xterm-true-color|
 	t_8b	set background color (R, G, B)			*t_8b* *'t_8b'*
 		|xterm-true-color|
+	t_8u	set underline color (R, G, B)			*t_8u* *'t_8u'*
 	t_BE	enable bracketed paste mode			*t_BE* *'t_BE'*
 		|xterm-bracketed-paste|
 	t_BD	disable bracketed paste mode			*t_BD* *'t_BD'*