“Tagging” is the labelling of photos and videos, primarily on Facebook but also elsewhere, with the names of people depicted. Sometimes, tags are also used to alert other people not in the original photo/video about interesting content.
Younger children probably won’t have their own social media accounts, so direct tagging of photos and videos shouldn’t be a problem, but teenagers may well have an account.
Suggest that friends and family either don’t tag at all, or tag you and not your kids.
Suggest that any of your kids with existing accounts carefully handle tags from friends, particularly when photos are taken in highly recognisable places, regularly visited places (e.g schools, town centres).