CS question: do private function namechanges count as API changes?

Hello, I'm currently working on Net_FTP, mainly to fix some bugs. But as I would like to get used to the PEAR codestyle, I started making the file PEAR CS compliant. One of the remaining errors is that some methods are not in camelcase (such as _determine_os_match). All of those methods are declared private in the php docs, as Net_FTP is PHP 4 compliant. I've read that API changes are not recommended, but do private method changes count as API methods? And should I change it to determineOSMatch(), _determineOSMatch() or perhaps (_)determineOsMatch()? Besides that, what would be the correct way of keeping line 572 [1] within the required 85 character / line limit? It's a variable defined in the class, so tricks like splitting the string do not help. Thanks for your advice, Jorrit Schippers [1] quicklink to file: http://cvs.php.net/viewvc.cgi/pear/Net_FTP/Net/FTP.php?view=annotate