MY_ prefixed classes -- reason for the prefix?

[eluser]jedd[/eluser]
[quote author="philpem" date="1255957573"]
I've got an application that extends the Controller class as MY_Controller to provide authentication functionality for the various functions. Basically, if a class extends MY_Controller, then you can't access it unless you have logged in, your session is valid (i.e. not timed out), and so forth.
[/quote]

You might have an easier time of it if you just change your code (in MY_Controller) to distinguish between admin and logged in and not-logged in users. Session data is a good way of accomplishing this.

That way you just need a single extended controller class.

This got me thinking -- the CodeIgniter docs explain that you have to use the MY_ prefix (or whatever subclass_prefix is set to), but doesn't go into any further detail. Just out of curiosity, why is this necessary?

I presume it's so CI can locate / identify the file fast - without needing to do directory scans, let alone reading class names within each file in there.

Plus, nomenclatures are generally good things in and of themselves.