The document to read, which covers all pertinent aspects of flag etiquette and suggested behavior during flag ceremonies and the pledge of allegiance (as well as legal history) is Federal Law Relating to Display and Associated Questions - usflag.pdf (my emphasis): (law.stackexchange.com)
Rear Adm. Francis Pelkowski, center watching the Old Glory Flag Ceremony during his retirement ceremony after 38 years of service at West Islip Fire Station, in West Islip Saturday May 19, 2018 (newsday.com)
- Elgin: The City of Elgin will hold a flag ceremony at 9 p.m. and fireworks at 9:30 p.m. Thursday at Elgin High School, 1200 Maroon Drive. (articles.chicagotribune.com)