Headers are technically implemented as a special entry in the variables dictionary, but they are special treated and should not make them appear as variables. If so, I will need to fix this. Where do you mean that they appear as variables exactly?
Headers will show up during a search (that control that shows up when you right click the canvas).
For instance, I have a “Currently Selected…” header, and a bunch of variables in the form of “Currently Selected Unit,” “Currently Selected Ability,” etc.
Searching for “Currently Selected” also lists the header, “Currently Selected…”