/**********************************************************************
 * The purpose of this snippet is to add in antiflag functionality in *
 * SmaugFUSS1.9.  This is set up for version 1.9, but shouldn't be    *
 * difficult to retrofit to the earlier versions of the project.      *
 *                                                                    *
 * If you would like to contact me, feel free to do so via a PM on    *
 * smaugmuds.org, my screen name is Aurin.                            *
 *                                                                    *
 * Cheers,                                                            *
 * Aurin                                                              *
 **********************************************************************/

In act_obj.c:
1. Find "Local Functions" at the top and add in at the bottom:
bool anticheck          args((CHAR_DATA *ch, OBJ_DATA *obj));

2. In function do_wear, find:
   if( !str_cmp( arg1, "all" ) )
   {
      OBJ_DATA *obj_next;

      for( obj = ch->first_carrying; obj; obj = obj_next )
      {
         obj_next = obj->next_content;
         if( obj->wear_loc == WEAR_NONE && can_see_obj( ch, obj ) )
         {
            wear_obj( ch, obj, FALSE, -1 );
            if( char_died( ch ) )
               return;
         }
      }
      return;
   }
   else
   {
      if( ( obj = get_obj_carry( ch, arg1 ) ) == NULL )
      {
         send_to_char( "You do not have that item.\r\n", ch );
         return;
      }
      if( arg2[0] != '\0' )
         wear_bit = get_wflag( arg2 );
      else
         wear_bit = -1;
      wear_obj( ch, obj, TRUE, wear_bit );
   }
   
change to:

   // Updated to prevent the wearing of anti-flagged items. - Aurin
   if( !str_cmp( arg1, "all" ) )
   {
      OBJ_DATA *obj_next;

      for( obj = ch->first_carrying; obj; obj = obj_next )
      {
         obj_next = obj->next_content;
         if( obj->wear_loc == WEAR_NONE && can_see_obj( ch, obj ) )
         {
		    if(anticheck(ch, obj))
		       continue;
            wear_obj( ch, obj, FALSE, -1 );
            if( char_died( ch ) )
               return;
         }
      }
      return;
   }
   else
   {
      if( ( obj = get_obj_carry( ch, arg1 ) ) == NULL )
      {
         send_to_char( "You do not have that item.\r\n", ch );
         return;
      }
	  if(anticheck(ch, obj))
	     return;
      if( arg2[0] != '\0' )
         wear_bit = get_wflag( arg2 );
      else
         wear_bit = -1;
      wear_obj( ch, obj, TRUE, wear_bit );
   }
	  
3. Just above the do_remove function add:

/* Wow...the anti-class flags were made, but never implemented.
 * Time to implement them. - Aurin 11/1/2011
 */
bool anticheck(CHAR_DATA *ch, OBJ_DATA *obj)
{
    if((IS_OBJ_STAT(obj, ITEM_ANTI_WARRIOR) && ch->Class == 4)
	   || (IS_OBJ_STAT(obj, ITEM_ANTI_MAGE) && ch->Class == 2)
	   || (IS_OBJ_STAT(obj, ITEM_ANTI_THIEF) && ch->Class == 6)
	   || (IS_OBJ_STAT(obj, ITEM_ANTI_CLERIC) && ch->Class == 0)
	   || (IS_OBJ_STAT(obj, ITEM_ANTI_VAMPIRE) && ch->Class == 15)
	   || (IS_OBJ_STAT(obj, ITEM_ANTI_DRUID) && ch->Class == 1))	   
    {
	   ch_printf(ch, "That item is Anti-%s, you cannot wear it.\r\n", class_table[ch->Class]->who_name);
	   return TRUE;
    }
	if(IS_OBJ_STAT(obj, ITEM_ANTI_GOOD) && ch->alignment > 350)
	{
	   ch_printf(ch, "That item is Anti-Good, you cannot wear it.\r\n");
	   return TRUE;
	}
	else if(IS_OBJ_STAT(obj, ITEM_ANTI_NEUTRAL) && ch->alignment >= -350 && ch->alignment <= 350)
	{
	   ch_printf(ch, "That item is Anti-Neutral, you cannot wear it.\r\n");
	   return TRUE;
	}
	else if(IS_OBJ_STAT(obj, ITEM_ANTI_EVIL) && ch->alignment < -350)
	{
       ch_printf(ch, "That item is Anti-Evil, you cannot wear it.\r\n");
	   return TRUE;
	}
	
	// If we get here, there is no anti-flag as described above.
	return FALSE;
}