Magento uses codding standards, based on Zend Framework codding standards.
See naming convention here: http://framework.zend.com/manual/1.12/en/coding-standard.naming-conventions.html
Pay attention to "Variables" section (follow the "camelCaps" capitalization convention) and http://framework.zend.com/manual/1.12/en/coding-standard.coding-style.html to Control Statements section.