OK, these are just small errors I've been noticing:

socket_set_timeout() - last argument is optional and is no shown as such

declare() - does not need to be called as a statement, this is valid:

declare(ticks=1);
rest of pages code here;

in which case its the same as doing:
declare(ticks=1) {
    rest of pages code here;
}

meaning that in the first, the ticks is on all the code following, whereas with the second you can have it only work for the code inside the statement.

register_tick_function - this does not state you use an object method as the callback method (using array(&$object,'method')

pcntl_waitpid - second argument should be noted as a reference (i.e. int &status)

Thats all I can remember right now, apart from the following need full docs:

pcntl_exec()
posix_ctermid()
posix_getcwd()
posix_getgrgid()
posix_getgrname()
posix_getrlimit()
posix_isatty()
posix_ttyname()
socket_get_option()
socket_iovec_*()
socket_readv()
socket_recv*()
socket_send*()
socket_set_nonblock()
socket_set_option()
socket_shutdown()
socket_writev()

quite a list. I would gladly help provide some documentation either as DocBook XML (as best I can, I'm still very new to it) or plaintext for you convert to DocBook...

- Davey