Some pages seem to be missing in the CHM variant of the manual(as per a 28th of February 2012 download).
At least, the pages for the sprintf and soundex functions(both can be found at "PHP Manual" -> "Function Reference" -> "Text Processing" -> "Strings" -> "String Functions") are missing(just a blank page). I am using the xCHM Linux application to browse the CHM file. Regards, Carl Michael Skog