<?xml version="1.0" encoding="UTF-8" ?> <COMPATIBILITY_MATRIX> <PLUGIN name="qtype_stack"> <PHP_EXTENSIONS> <PHP_EXTENSION name="mbstring" level="required"> <FEEDBACK> <ON_ERROR message="mbstringrequired" plugin="qtype_stack" /> </FEEDBACK> </PHP_EXTENSION> <PHP_EXTENSION name="yaml" level="optional"> <FEEDBACK> <ON_CHECK message="yamlrecommended" plugin="qtype_stack" /> </FEEDBACK> </PHP_EXTENSION> </PHP> </PLUGIN> </COMPATIBILITY_MATRIX>