You're probably saying "what is he talking about?" In this world of radio digitization and automation we have to pay close attention to every detail. When you set up radio automation, there is usually an option that enables to force stop and play the stations legal ID or make a natural transition and play the legal ID when the element on the air is over.
The FCC says that a station's legal ID must be played at the top of the hour or as close as possible. If a programmer chooses to "Force Stop," whatever is playing on the air will quickly fade out exactly at the top of the hour and the ID will play. If you choose a natural transition, the ID will play at the natural program break. For example if your are programming music, the last song will play through even if it goes over the top of the hour a minute or two, then the Legal ID will play.
I always opt for a natural transition and play the ID when a song is over as close as possible to the top of the hour.
Please note there are several circumstances where a forced stop is necessary. One may be if you are playing another stream during certain hours.
In this day and age, the technology is wonderful but there are so many small details that you must pay attention to.