Schematics and board for Mega 2560 R3

Hi,

Would someone be kind enough to point me to the schematics and any documentation of things like what the four pads near the USB socket are for? I have just bought an R3 and find that the obvious schematics on the website do not match the hardware that I have.

Thanks in advance, Brian.

They seem to connect to the 16U2 pins 18, 19, 20, 21, for who knows what.
Maybe general purpose I/O for future expansion.