The Chicago Diner

Source: r/Chicago restaurant surcharge spreadsheet (crowdsourced), reported date unavailable (circa 2023; not re-verified). Surcharge: 20. Notes: "A 20% gratuity is added for all dine-in. Tips are equally shared between all service team members." Automatic 20% gratuity, but they don't mention it when giving you the card-reader, which also displays a tip screen

Source: The Chicago Diner official online menu (live page, verified 2026-09-11, https://veggiediner.com/menus/): a 20% gratuity is automatically added ONLY for parties larger than five; it is not a venue-wide policy. Report date: 2026-09-11 (high confidence; live official source, party-size-limited policy).