Much as we fidgeted through Bruni’s lecture on tipping yesterday, we’re glad to see Voice critic Robert Sietsema open up a conversation about tipping at takeout counters. Rather than imparting wisdom, Sietsema merely points out that they seem to be a recent development, brought on by the advent of baristas — and now omnipresent (and increasingly annoying). We’ve already learned to tip delivery guys generously, given all the exposés about how little they’d be compensated otherwise. But how do you handle the tip jars at cafés, slice joints, and the like? Are there any counter-people out there who care to explain how the system works? Do you expect a 15 to 20 percent tip, and are you a jackass if you drop change in Artichoke’s “tips for the boys” jar instead of a proper buck? (We certainly feel guilty every time our change clinks incriminatingly in Despaña’s silver tip tray.) Customers, what are your rules about tipping in a takeout situation?