===================================================================
RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/fmt/fmt.1,v
retrieving revision 1.27
retrieving revision 1.28
diff -u -r1.27 -r1.28
--- src/usr.bin/fmt/fmt.1	2015/09/11 19:20:18	1.27
+++ src/usr.bin/fmt/fmt.1	2015/12/15 16:26:17	1.28
@@ -1,4 +1,4 @@
-.\" $OpenBSD: fmt.1,v 1.27 2015/09/11 19:20:18 schwarze Exp $
+.\" $OpenBSD: fmt.1,v 1.28 2015/12/15 16:26:17 schwarze Exp $
 .\"
 .\" Copyright (c) 1980, 1990, 1993
 .\"	The Regents of the University of California.  All rights reserved.
@@ -29,7 +29,7 @@
 .\"
 .\"     @(#)fmt.1	8.1 (Berkeley) 6/6/93
 .\"
-.Dd $Mdocdate: September 11 2015 $
+.Dd $Mdocdate: December 15 2015 $
 .Dt FMT 1
 .Os
 .Sh NAME
@@ -139,6 +139,19 @@
 evening the lines:
 .Pp
 .Dl !}fmt
+.Sh ENVIRONMENT
+.Bl -tag -width LC_CTYPE
+.It Ev LC_CTYPE
+The character set
+.Xr locale 1 .
+It is used to decide which byte sequences form characters and what
+their display width is.
+If it is unset or set to
+.Qq C ,
+.Qq POSIX,
+or an unsupported value, each byte except the tab is assumed
+to represent a character of display width 1.
+.El
 .Sh EXIT STATUS
 .Ex -std
 The latter happens with invalid options, insufficient memory,