Am I allow to prefix interface class names with the letter "I"

As title, am I allow to prefix my interface class with the letter "I"?

The reason why Yii classes are prefixed with the letter ‘C’ is that PHP does not have namespace support.

Starting with PHP 5.3.x it does.

If the class name doesn’t clash with other class names, then it should be alright.

You are allowed to do anything :) - the question is, wether it’s a whise thing to do:

  1. Others (and maybe yourself in some month) might be confused wether something is a framework or a custom interface if you use the same naming scheme

  2. You will have troubles if some day the framework introduces an interface with the same name

Totally agree