When you have a template class which takes a bool as argument, you may end up writing code like:
myclass<(varX <= 10)> varY; // when varX less or equal 10
myclass<(varX >= 10)> varY;
In both cases, VAX treats the operator wrongly and colors varY in black as unknown symbol.
One may have the same problem with other types of templates too. As soon as you use any of the angle bracket operators inside a template instantiation.