doctrine2/manual/docs/Coding standards - Naming Conventions - Filenames.php

<ul>
<li \>For all other files, only alphanumeric characters, underscores, and the dash character ("-") are permitted. Spaces are prohibited.
</ul>

<ul>
<li \>Any file that contains any PHP code must end with the extension ".php". These examples show the acceptable filenames for containing the class names from the examples in the section above:
 <br \>    <br \>
Doctrine/Db.php <br \>
                       <br \>
Doctrine/Connection/Transaction.php <br \>
</ul>
<ul>
<li \>File names must follow the mapping to class names described above.
</ul>