This is not an important question but it's really bothering me more than it should.
Is there any reason why the parallel gateway is represented by a perpendicular sign?
Or is this the addition symbol? Signifying that all events occur together... thus plus?
Ugh, it is a plus sign. As stated in the specifications http://www.omg.org/spec/BPMN/2.0/
It just seemed more intuitive to me to represent it with parallel lines when naming it parallel gateway.