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 8.9% of the 14442 total user notes.
Notes | Page -------+--------------------------------------------------------- 86 | http://php.net/manual/en/function.header.php 85 | http://php.net/manual/en/function.preg-replace.php 79 | http://php.net/manual/en/ref.xml.php 73 | http://php.net/manual/en/ref.image.php 72 | http://php.net/manual/en/ref.session.php 69 | http://php.net/manual/en/function.mktime.php 66 | http://php.net/manual/en/reserved.variables.php 62 | http://php.net/manual/en/function.strtotime.php 61 | http://php.net/manual/en/function.mssql-connect.php 61 | http://php.net/manual/en/features.file-upload.php 61 | http://php.net/manual/en/function.readdir.php 60 | http://php.net/manual/en/function.fsockopen.php 60 | http://php.net/manual/en/function.strpos.php 59 | http://php.net/manual/en/function.str-replace.php 58 | http://php.net/manual/en/ref.com.php 57 | http://php.net/manual/en/function.array-search.php 56 | http://php.net/manual/en/function.date.php 55 | http://php.net/manual/en/function.serialize.php 54 | http://php.net/manual/en/ref.exec.php 54 | http://php.net/manual/en/ref.mail.php