All Solar class names start with a vendor name prefix and map directly to their filesystem location, where underscores are replaced with directory separators. This is called the "class-to-file" convention, and is in conformance with the older PEAR class naming standard and the newer PSR-0 standard.

The Solar vendor name is Solar. For example, the Solar_Auth_Adapter_Sql class is located at Solar/Auth/Adapter/Sql.php.

When you write your own classes, you should pick a unique vendor name for them. The vendor name should begin with a capital letter and be followed only by lower-case letters and/or numbers. Do not use studly- or camel-cased vendor names; if you do, the inflection that converts vendor names to all lower case for command-line interfaces may not handle it properly in all cases. (Studly- or camel-cased portions of the class name *after* the initial vendor portion are acceptable but discouraged.)