diff --git a/runtime/doc/options.txt b/runtime/doc/options.txt
index 9fab3f4..089df14 100644
--- a/runtime/doc/options.txt
+++ b/runtime/doc/options.txt
@@ -3621,6 +3621,7 @@
 	  lastline	'@'		'display' contains lastline/truncate
 	  trunc		'>'		truncated text in the
 					|ins-completion-menu|.
+	  truncrl	'<'		same as "trunc' in 'rightleft' mode
 
 	Any one that is omitted will fall back to the default.
 
@@ -3645,6 +3646,7 @@
 	  lastline	NonText			|hl-NonText|
 	  trunc		one of the many Popup menu highlighting groups like
 			|hl-PmenuSel|
+	  truncrl	same as "trunc"
 
 						*'findfunc'* *'ffu'* *E1514*
 'findfunc' 'ffu'	string	(default empty)