Yes, when I worked in a school. I was a secretary there so I had control of coming and going & took it very seriously You'd be shocked how many parents pushed up against the rules of announcing who you were and why you were there, like they should get a pass.
People need to know that they really need to be supportive of school security, it is not a good thing to give people a pass because you never know if a POA pops up or if, say there is some conflict in the family or friends. Not just for kids but teachers and other staff too, the secretary would not be the first one you'd tell but you should, I NEVER let anyone in without announcing themselves.
Showing up in a uniform was not gonna help I'd get the janitor to escort everyone and if no-one told me to expect someone guess who was not getting a buzz? Ticked off, too bad, go away.