I'm just a volunteer with no life, I don't know about the inner workings of the "powers that be". I suspect its an oversight, the stuff is widely available all over the net. The Uno is largely the same as earlier model Arduinos, The Duemilanove was around a while and is largely similar so most stuff for the Duemilanove also applies to the UNO.
ICSP - basically SCK,MISO,MOSI, Reset, 5V & Gnd as per schematic :