I was at an event with high ranking Japanese personal, heads of a martial arts organisation. People were asking for signatures on event passes, which had their name written on it. As part of the signature, one gentleman was writing the participants name:
On the pass.
On mine however, he wrote:
I have read about the formality of using 氏, as used when you do not know or have never met the person, however we have met many times, both training together and meals, parties etc. I have great respect for him, and he knows me by name, so I was wondering if there is anything else about the use of 氏 in this case I can learn.