...is The Healthy San Francisco Surcharge they add to your restaurant bill. "This fee allows restaurateurs to help pay for the city's health care program. The small charges vary: Some are a percentage of the total (usually around 4 percent), others tack on a dollar or two.
Not all restaurants include the charge, but by city mandate, all businesses with 20-plus employees have to either offer health insurance or help pay for the city's health care access program, Healthy San Francisco. HSF isn't insurance, per se, but it does offer affordable health care for uninsured residents of the city who don't qualify for Medicare or Medi-Cal."*
*Quoted from here.