SAN DIEGO — This Independence Day weekend will be especially sweet for Americans, who will be liberated from many of the COVID-19 protocols they followed this time last year. But there still are things to keep in mind before heading out. Masks and social distancing rules still are required in some places and there are different rules for people who are vaccinated and those who are not. If you’re fully vaccinated, you won’t need a mask when meeting friends inside your favorite restaurant. If you’re catching a bus or trolley to that restaurant, however, you still have to wear a mask. Metropolitan Transit System requires everyone to wear a face covering while riding one of its vehicles and while waiting at a stop or at an MTS station. North County Transit District is abiding by the same protocols.