Following are the top 20 pages of the manual, sorted by the number of user notes contributed. These sections could use a polish, those notes represent 9.1% of the 13748 total user notes.
Notes | Page -------+--------------------------------------------------------- 89 | http://php.net/manual/en/function.header.php 87 | http://php.net/manual/en/function.date.php 74 | http://php.net/manual/en/function.preg-replace.php 73 | http://php.net/manual/en/ref.xml.php 71 | http://php.net/manual/en/reserved.variables.php 67 | http://php.net/manual/en/ref.image.php 62 | http://php.net/manual/en/function.eval.php 62 | http://php.net/manual/en/ref.session.php 62 | http://php.net/manual/en/function.mktime.php 59 | http://php.net/manual/en/function.mssql-connect.php 58 | http://php.net/manual/en/function.fopen.php 57 | http://php.net/manual/en/features.file-upload.php 57 | http://php.net/manual/en/ref.com.php 56 | http://php.net/manual/en/function.fsockopen.php 56 | http://php.net/manual/en/function.readdir.php 55 | http://php.net/manual/en/function.explode.php 54 | http://php.net/manual/en/function.str-replace.php 53 | http://php.net/manual/en/function.exec.php 52 | http://php.net/manual/en/function.strtotime.php 52 | http://php.net/manual/en/function.strpos.php