BBCode?

The RTE dosn't do any form processing as it is made to apply to already built projects to simply turn any text area into an Rich Text Area.

It simply sites over the top of your existing forms text area and transforms it into an RTE area allowing HTML to be used in a WYSIWYG mode.

This means that any form processing such as filtering or converting the form content needs to be handled by your pre-existing code.

Things such as BBCode is handled by whatever process you submit the form to, so you would need to build into your code yourself any filters such as this.