It’s correct when written because acronyms are representing the words the abriviate. In this case an unidentified object. If you where to speak the acronym than just “a” is correct because you are saying the letter “U” not the word “unidentified”. Does that make sense. Different rules for written and spoken.

🏴‍☠️rrrr haha😋

Auto up vote for using “an” correctly.

If every meeting goes like this maybe it will bring peace. Zzzzzz

I bet the code is cracked within the hour of every update from now until eternity. It’s like the shit physical locks we put on everything. Nothing but a display of safety.