From the 'Coding Standards' section of the PEAR Manual (http://pear.php.net/manual/). Classes should be given descriptive names, e.g. *TemperatureControl*, *HTML_Table*. Public method and variable names should follow the 'Camel caps' (aka 'Studly caps') convention, except for the class constructor, e.g. *addRow()*, *HTML_Table()*. Private method and variable names should start with an underscore '*_*', e.g. *_formatBorder()*, *$this->_numRows*. Constants should be all uppercase and prefixed with the name of the package, e.g. define('*MATH_STATS_CUMMULATIVE*',1); If you need to define _global_ variables, their names should be prefixed with the package name and start with an underscore, e.g. $GLOBALS['*_PEAR_default_error_mode*']