Greetings! Another change request to the reference docs.
From EthernetUdp.h
// Write size bytes from buffer into the packet
virtual size_t write(const uint8_t *buffer, size_t size);
The following additions should be added to this page:
http://arduino.cc/en/Reference/EthernetUDPWrite
Syntax
UDP.write(message);
UDP.write(buf,len);
Parameters
message: the outgoing message (char)
buf: an array to send as a series of bytes (byte or char)
len: the length of the buffer
edit: This addition allows you to send zeros in the packet.
I emailed this to the webmaster@arduino.cc also.