.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
-.\" 3. All advertising materials mentioning features or use of this software
-.\" must display the following acknowledgement:
-.\" This product includes software developed by the University of
-.\" California, Berkeley and its contributors.
.\" 4. Neither the name of the University nor the names of its contributors
.\" may be used to endorse or promote products derived from this software
.\" without specific prior written permission.
.\" SUCH DAMAGE.
.\"
.\" @(#)isblank.3 8.1 (Berkeley) 6/4/93
-.\" $FreeBSD: src/lib/libc/locale/isblank.3,v 1.17 2002/12/18 12:45:08 ru Exp $
+.\" $FreeBSD: src/lib/libc/locale/isblank.3,v 1.26 2009/11/11 11:31:02 roam Exp $
.\"
-.Dd October 6, 2002
+.Dd July 17, 2005
.Dt ISBLANK 3
.Os
.Sh NAME
.It "\&``\et''\t`` ''"
.El
.Pp
-In the "C" locale
+In the "C" locale, a successful
.Fn isblank
-successful test is limited to this characters only.
-For single C
-.Va char Ns s
-locales (see
-.Xr multibyte 3 )
-the value of the argument is
-representable as an
-.Li unsigned char
+test is limited to these characters only.
+The value of the argument must be representable as an
+.Vt "unsigned char"
or the value of
.Dv EOF .
-.Sh COMPATIBILITY
-Although
-.Fn isblank
-accepts arguments outside of the range of the
-.Vt "unsigned char"
-type in locales with large character sets,
-this is a
-.Bx 4.4
-extension and the
-.Fn iswblank
-function should be used instead for maximum portability.
.Sh RETURN VALUES
The
.Fn isblank
function returns zero if the character tests false and
returns non-zero if the character tests true.
+.Sh COMPATIBILITY
+The
+.Bx 4.4
+extension of accepting arguments outside of the range of the
+.Vt "unsigned char"
+type in locales with large character sets is considered obsolete
+and may not be supported in future releases.
+The
+.Fn iswblank
+function should be used instead.
.Sh SEE ALSO
.Xr ctype 3 ,
+.Xr isalnum_l 3 ,
.Xr iswblank 3 ,
-.Xr multibyte 3 ,
.Xr ascii 7
.Sh STANDARDS
The