What's the most unusual way you have seen someone receive notification of promotion?

My CO thought it was funny to announce the e6 results over the announcing circuit while I was standing quarterdeck watch. He left my name out on purpose and didnt tell me I made it until I got relieved for lunch. I guess the CMC told him to do it because he thought it would be funny since it took me longer than usual to make e6 due to previously being masted from e5 to e4

I called all my SSGs forward in front of the formation. Then I used the old joke. I then said that I wanted all my SSGs to take one step backward. As they all moved back one step, I asked SSG XXXX where was he going. He stood fast and we began his promotion ceremony. Not original by any means, but it was fun and we watched a deserving NCO get his just reward.

During PT

1962. Carrier operating in westpac. 1st class MM was called to mess decks. He had been involved in overhauling a pump and looked like it. He had taken the CPO exam and apparently aced it. A team of navy Chiefs flew aboard and gave him another test to verify he had not somehow cheated on the original test. He missed only one question on the second test. The ship's Captain was present when the 1st class was informed of the results. The Captain immediately came up, offered his hand, and said "Congratulations Chief. Move into the CPO quarters immediately. The 1sr class stated his thanks and that he would move when he finished the pump overhaul. Seems as if he had some junior sailors he was teaching regarding pump overhaul.

My coworker made A1C (E-4) and the office was decked out with signs of congratulations for her accomplishment. It was not easy in those days. Then someone found out that I also made A2C and my name was added to a sign with a piece of scratch paper saying and A@C Porter

As a E-3 - Safety briefing for 4th of July weekend. Got called in front of BN, and was told had a three pass (4 day weekend) and as a new SPC had duty on Sunday. Then got pinned and released until Sunday.

He was me crew chief in Korea and on leave down town in his huse and i went down and gave him the papers so he could wear it to work in 21 days.

Saw a coach get his announcement from the tower on the firing line at Parris Island

An extremely unfortunate series of events led to one of my coworkers not knowing he made E-5 until a year after the fact. I'm not admin, so how any of this happened and how many people dropped the ball is unknown to me. This is all through the grapevine, but what I can confirm is that he DID wear the wrong rank for a year.
So he tested for Staff, didn't really study for it or feel that confident about it, so he didn't bother checking for his name when the results came out; his name WAS on it.
There was an outage down at AFPC not long after the results were released, and his records were corrupted. They called up to our squadron and asked for promotion numbers. The CSS had the list saved, but, somehow, missed his name on it when provided the information, so AFPC populated the promotion list without him on it. The commander was CC'd, and trusted it, so she never bothered checking the list to see if that was true.
Somewhere in all that, MILPDS semi-updated with his proper information, but provided no notification to anybody, to include DFAS, which continued disbursing E-4 pay.
Well, everyone starts getting WAPS notices next year, save for him. He had actually been studying and felt confident, so he got worried when it was getting time to sign his paperwork and nothing was coming down. So he talked to CSS who went into his MILPDS....and found out he had been E-5 for about ten months already. It was a massive scramble and a blur at that point. Phones were exploding, paperwork was everywhere. He got one Hell of a payout from DFAS in backpay and allowances and immediately sewed on Staff.

I was sleeping outside a vehicle at a compound in Kandahar province. My Squad leader woke me up at 0200ish and told me I needed to get up and check the BFT, my PSG sent a message to let me know I was now a SGT