Class filenames should always start with an uppercase letter, while any other file name (configurations, views, generic scripts, etc.) should all be in lowercase.
Class file names should match the name of the class itself. For example, if you have a class named MyClass, then its filename should also be MyClass.php.
Multiple words should be separated with an underscore.
INCORRECT
someclass.php
someClass.php
SOMECLASS.php
Some_Class.php
Some_class.php
Someclass.php
CORRECT
SomeClass.php
Class file names should match the name of the class itself. For example, if you have a class named MyClass, then its filename should also be MyClass.php.
Multiple words should be separated with an underscore.
INCORRECT
someclass.php
someClass.php
SOMECLASS.php
Some_Class.php
Some_class.php
Someclass.php
CORRECT
SomeClass.php