From the Document: "The 'flag code' is the federal law that sets forth guidelines for the appearance and display of the U.S. flag ('flag') by private citizens. These guidelines specify times and conditions for display of the flag, manners and methods of display, and buildings where such display should occur. The guidelines for flag display vary based on the context and occasion, and there are detailed specifications for displaying flags at 'half-staff.' The flag code also specifies how to deliver the Pledge of Allegiance to the flag and appropriate conduct while watching a performance of the National Anthem. Most of the flag code contains no explicit enforcement mechanisms, and relevant case law would suggest that the provisions without enforcement mechanisms are declaratory and advisory only."
CRS Report for Congress, R45945
Congressional Research Service: https://crsreports.congress.gov/