diff -up shadow-4.1.5.1/libmisc/chkname.c.goodname shadow-4.1.5.1/libmisc/chkname.c
--- shadow-4.1.5.1/libmisc/chkname.c.goodname	2009-07-13 00:24:45.000000000 +0200
+++ shadow-4.1.5.1/libmisc/chkname.c	2012-09-19 18:43:53.492160653 +0200
@@ -49,20 +49,28 @@
 static bool is_valid_name (const char *name)
 {
 	/*
-	 * User/group names must match [a-z_][a-z0-9_-]*[$]
-	 */
-	if (('\0' == *name) ||
-	    !((('a' <= *name) && ('z' >= *name)) || ('_' == *name))) {
+         * User/group names must match gnu e-regex:
+         *    [a-zA-Z0-9_.][a-zA-Z0-9_.-]{0,30}[a-zA-Z0-9_.$-]?
+         *
+         * as a non-POSIX, extension, allow "$" as the last char for
+         * sake of Samba 3.x "add machine script"
+         */
+	if ( ('\0' == *name) ||
+             !((*name >= 'a' && *name <= 'z') ||
+               (*name >= 'A' && *name <= 'Z') ||
+               (*name >= '0' && *name <= '9') ||
+               (*name == '_') || (*name == '.') 
+	      )) {
 		return false;
 	}
 
 	while ('\0' != *++name) {
-		if (!(( ('a' <= *name) && ('z' >= *name) ) ||
-		      ( ('0' <= *name) && ('9' >= *name) ) ||
-		      ('_' == *name) ||
-		      ('-' == *name) ||
-		      ( ('$' == *name) && ('\0' == *(name + 1)) )
-		     )) {
+                if (!(  (*name >= 'a' && *name <= 'z') ||
+                        (*name >= 'A' && *name <= 'Z') ||
+                        (*name >= '0' && *name <= '9') ||
+                        (*name == '_') || (*name == '.') || (*name == '-') ||
+                        (*name == '$' && *(name + 1) == '\0') 
+                     )) {
 			return false;
 		}
 	}
diff -up shadow-4.1.5.1/man/groupadd.8.xml.goodname shadow-4.1.5.1/man/groupadd.8.xml
--- shadow-4.1.5.1/man/groupadd.8.xml.goodname	2012-05-25 13:45:27.000000000 +0200
+++ shadow-4.1.5.1/man/groupadd.8.xml	2012-09-19 18:43:53.492160653 +0200
@@ -259,12 +259,6 @@
    <refsect1 id='caveats'>
      <title>CAVEATS</title>
      <para>
-       Groupnames must start with a lower case letter or an underscore,
-       followed by lower case letters, digits, underscores, or dashes.
-       They can end with a dollar sign.
-       In regular expression terms: [a-z_][a-z0-9_-]*[$]?
-     </para>
-     <para>
        Groupnames may only be up to &GROUP_NAME_MAX_LENGTH; characters long.
      </para>
      <para>
diff -up shadow-4.1.5.1/man/man8/groupadd.8.goodname shadow-4.1.5.1/man/man8/groupadd.8
--- shadow-4.1.5.1/man/man8/groupadd.8.goodname	2012-05-25 13:58:40.000000000 +0200
+++ shadow-4.1.5.1/man/man8/groupadd.8	2012-09-19 18:44:42.175123079 +0200
@@ -190,9 +190,7 @@ Shadow password suite configuration\&.
 .RE
 .SH "CAVEATS"
 .PP
-Groupnames must start with a lower case letter or an underscore, followed by lower case letters, digits, underscores, or dashes\&. They can end with a dollar sign\&. In regular expression terms: [a\-z_][a\-z0\-9_\-]*[$]?
-.PP
-Groupnames may only be up to 16 characters long\&.
+Groupnames may only be up to 32 characters long\&.
 .PP
 You may not add a NIS or LDAP group\&. This must be performed on the corresponding server\&.
 .PP
diff -up shadow-4.1.5.1/man/man8/useradd.8.goodname shadow-4.1.5.1/man/man8/useradd.8
--- shadow-4.1.5.1/man/man8/useradd.8.goodname	2012-05-25 13:59:28.000000000 +0200
+++ shadow-4.1.5.1/man/man8/useradd.8	2012-09-19 18:46:09.249033949 +0200
@@ -224,7 +224,7 @@ is not enabled, no home directories are
 .PP
 \fB\-M\fR
 .RS 4
-Do no create the user\*(Aqs home directory, even if the system wide setting from
+Do not create the user\*(Aqs home directory, even if the system wide setting from
 /etc/login\&.defs
 (\fBCREATE_HOME\fR) is set to
 \fIyes\fR\&.
@@ -430,8 +430,6 @@ Similarly, if the username already exist
 \fBuseradd\fR
 will deny the user account creation request\&.
 .PP
-Usernames must start with a lower case letter or an underscore, followed by lower case letters, digits, underscores, or dashes\&. They can end with a dollar sign\&. In regular expression terms: [a\-z_][a\-z0\-9_\-]*[$]?
-.PP
 Usernames may only be up to 32 characters long\&.
 .SH "CONFIGURATION"
 .PP
diff -up shadow-4.1.5.1/man/useradd.8.xml.goodname shadow-4.1.5.1/man/useradd.8.xml
--- shadow-4.1.5.1/man/useradd.8.xml.goodname	2012-05-25 13:45:29.000000000 +0200
+++ shadow-4.1.5.1/man/useradd.8.xml	2012-09-19 18:43:53.493160675 +0200
@@ -366,7 +366,7 @@
 	</term>
 	<listitem>
 	  <para>
-	    Do no create the user's home directory, even if the system
+	    Do not create the user's home directory, even if the system
 	    wide setting from <filename>/etc/login.defs</filename>
 	    (<option>CREATE_HOME</option>) is set to
 	    <replaceable>yes</replaceable>.
@@ -654,12 +654,6 @@
     </para>
 
     <para>
-      Usernames must start with a lower case letter or an underscore,
-      followed by lower case letters, digits, underscores, or dashes.
-      They can end with a dollar sign.
-      In regular expression terms: [a-z_][a-z0-9_-]*[$]?
-    </para>
-    <para>
       Usernames may only be up to 32 characters long.
     </para>
   </refsect1>