PHP Manual . ... Next . ... About the incompatibilities in 3.0 . Start/end tags . if..endif syntax . ... Error messages have changed . ... PHP 3.0 is rewritten from the ground up. ... In addition, PHP's developers have tried to clean up both PHP's syntax and semantics in version 3.0, and this has also caused some incompatibilities. ... This chapter will try to guide you through the incompatibilities you might run into when going from PHP/FI 2.0 to PHP 3.0 and help you resolve them. ...