% operator in for loop (not module operator!)

I found some code written by a coworker by accident that compiles but we both do not know what it really means:

What does the % sign in following code do?

for (auto% layer : layers) { /* ...*/ }

This actually is a typo and was meant to be following:

for (auto &layer : layers) { /* ...*/ }

>Solution :

% is the c++-cli Tracking Reference Operator