Customers enjoy drinks outside a pub in Covent Garden on the last Saturday for shopping before Christmas, in central London on December 18, 2021. - The British government on Friday reported 93,045 new coronavirus cases, a third consecutive record daily tally, as the Omicron variant fuels a surge in infections across the country. Britain is currently rolling out a mass booster drive in order to vaccinate as many people as possible before the end of the year. (Photo by Tolga Akmen / AFP via Getty Images)
Efforts in Europe to encourage vaccine use through certificates proving vaccination, a negative test result or evidence of having had Covid have created a mountain of regulation.
Here are some of the more puzzling rules as Europeans settle for another winter holiday season overshadowed by the pandemic threat: