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

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

(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) Disable libxml errors and allow user to fetch error information as needed

(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