(PHP 5 >= 5.4.0, PHP 7) Changes the default external entity loader

(PHP 5 >= 5.1.0, PHP 7) Disable libxml errors and allow user to fetch error information as needed

(PHP 5, PHP 7) Set the streams context for the next libxml document load or write

(PHP 5 >= 5.1.0, PHP 7) Retrieve array of errors

(PHP 5 >= 5.1.0, PHP 7) Clear libxml error buffer

(PHP 5 >= 5.1.0, PHP 7) Retrieve last error from libxml

(PHP 5 >= 5.2.11, PHP 7) Disable the ability to load external entities