Add test for gettabvar() and settabvar().
diff --git a/runtime/doc/options.txt b/runtime/doc/options.txt
index 8c8006c..498df7f 100644
--- a/runtime/doc/options.txt
+++ b/runtime/doc/options.txt
@@ -1450,6 +1450,8 @@
 			as HTML.  This works to copy rendered HTML from
 			Firefox, paste it as raw HTML in Vim, select the HTML
 			in Vim and paste it in a rich edit box in Firefox.
+			You probably want to add this only temporarily,
+			possibly use BufEnter autocommands.
 			Only supported for GTK version 2 and later.
 			Only available with the |+multi_byte| feature.