--- coreutils-5.91.orig/src/sort.c	2005-10-07 19:16:56 +0000
+++ coreutils-5.91/src/sort.c	2005-10-20 12:44:08 +0000
@@ -2218,7 +2218,7 @@ main (int argc, char **argv)
 	{
 	case 1:
 	  key = NULL;
-	  if (obsolete_usage && optarg[0] == '+')
+	  if ((obsolete_usage || !posixly_correct) && optarg[0] == '+')
 	    {
 	      /* Treat +POS1 [-POS2] as a key if possible; but silently
 		 treat an operand as a file if it is not a valid +POS1.  */
--- coreutils-5.91.orig/src/tail.c	2005-10-14 13:56:44 +0000
+++ coreutils-5.91/src/tail.c	2005-10-20 12:47:51 +0000
@@ -1366,6 +1366,7 @@ parse_obsolete_option (int argc, char * 
   const char *p = argv[1];
   const char *n_string;
   const char *n_string_end;
+  bool posixly_correct;
   bool obsolete_usage;
   int default_count = DEFAULT_N_LINES;
   bool t_from_start;
@@ -1378,6 +1379,7 @@ parse_obsolete_option (int argc, char * 
   if (argc < 2)
     return false;
 
+  posixly_correct = (getenv ("POSIXLY_CORRECT") != NULL);
   obsolete_usage = (posix2_version () < 200112);
 
   switch (*p++)
@@ -1387,7 +1389,7 @@ parse_obsolete_option (int argc, char * 
 
     case '+':
       /* Leading "+" is a file name in the non-obsolete form.  */
-      if (!obsolete_usage)
+      if (!obsolete_usage && posixly_correct)
 	return false;
 
       t_from_start = true;
--- coreutils-5.91.orig/src/uniq.c	2005-07-05 07:38:37 +0000
+++ coreutils-5.91/src/uniq.c	2005-10-20 12:49:36 +0000
@@ -443,7 +443,7 @@ main (int argc, char **argv)
 	  {
 	    unsigned long int size;
 	    if (optarg[0] == '+'
-		&& posix2_version () < 200112
+		&& (posix2_version () < 200112 || !posixly_correct)
 		&& xstrtoul (optarg, NULL, 10, &size, "") == LONGINT_OK
 		&& size <= SIZE_MAX)
 	      skip_chars = size;