Several operators i (frequently) use are missing from the reference page:
arduino.cc/en/Reference/HomePage
The ones that are missing:
-Modulo assignment %=
-Bitwise XOR assignment ^=
-Bitwise left shift assignment <<=
-Bitwise right shift assignment >>=
Is there any reason why they where left out? Perhaps to prevent confusion amongst beginners? Well, this incompleteness did confuse me a little.
Also, just something i noticed. The increment and decrement operators are listed under the compound asignment operators, but in the wikipedia article they are listed under the Arithmetic operators.
I just found out where it was hidden all along. You have to click through to get to the Bit Math Tutorial and scroll down. I prefer shortcuts of operators close to the operators themselves.