Index: contrib/nvi/man/vi.1
===================================================================
--- contrib/nvi/man/vi.1
+++ contrib/nvi/man/vi.1
@@ -2743,6 +2743,10 @@
 .Xr ctags 1 ,
 .Xr iconv 1 ,
 .Xr re_format 7
+.Rs
+.%T vi/ex reference manual
+.%U https://docs.freebsd.org/44doc/usd/13.viref/paper.pdf
+.Re
 .Sh STANDARDS
 .Nm nex Ns / Ns Nm nvi
 is close to