[aix1]

What's a "pass back"? I'm guessing some form of fare dodging, but could you explain the mechanics?

[duskwuff]

I imagine it refers to entering the station using a ticket, then passing that ticket to someone leaving the station. (And, presumably, relying on someone else doing the same thing at the other end?)

[digianarchist]

Correct except fares are not routinely checked on the TTC so once you've entered you shouldn't experience any issues.