PHP 5.3.0 introduces two new error levels named as E_DEPRECATED and E_USER_DEPRECATED.

The E_DEPRECATED error level is used to indicate that a function or feature has been deprecated.

The E_USER_DEPRECATED level is intended for indicating deprecated features in user code, similarly to the E_USER_ERROR and E_USER_WARNING levels.

The following is a list of deprecated INI directives.
Use of any of these INI directives will cause an E_DEPRECATED.

define_syslog_variables
register_globals
register_long_arrays
safe_mode
magic_quotes_gpc
magic_quotes_runtime
magic_quotes_sybase
Comments starting with ‘#’ are now deprecated in .INI files.

Deprecated functions:

1.call_user_method()
  Can be used call_user_func() instead

2.call_user_method_array()
  Can be used call_user_func_array() instead

3.define_syslog_variables()
  dl()

4.ereg()
  Can be used preg_match() instead

5.ereg_replace()
  Can be used preg_replace() instead

6.eregi()
  Can be used preg_match() with the 'i' modifier instead

7.eregi_replace()
  Can be used preg_replace() with the 'i' modifier instead

8.set_magic_quotes_runtime() and its alias, magic_quotes_runtime()

9.session_register()
  Can be used the $_SESSION superglobal instead

10.session_unregister()
  Can be used the $_SESSION superglobal instead

11.session_is_registered()
  Can be used the $_SESSION superglobal instead

12.set_socket_blocking()
  Can be used stream_set_blocking() instead

13.split()
  Can be used preg_split() instead

14.spliti()
  Can be used preg_split() with the 'i' modifier instead

15.sql_regcase()

16.mysql_db_query()
  Can be used mysql_select_db() and mysql_query() instead

17.mysql_escape_string()
  Can be used mysql_real_escape_string() instead

18.Passing locale category names as strings is now deprecated. Use the LC_* family of constants instead.
  The is_dst parameter to mktime(). Use the new timezone handling functions instead.

Deprecated features:

       * Assigning the return value of new by reference is now deprecated.

       * Call-time pass-by-reference is now deprecated.

Deprecated variables:

HTTP_ENV_VARS  use $_ENV instead
HTTP_GET_VARS  use $_GET instead
HTTP_POST_VARS  use $_POST instead
HTTP_POST_FILES  use $_FILE instead
HTTP_COOKIE_VARS  use $_COOKIE instead
HTTP_SESSION_VARS  use $_SESSION instead

You should take care the above in the coding, so that the code will run new in versions of PHP also.

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