I’ve been noticing this when I send out mail at work, lately.
I’ve only ever seen it if that part of the address is an apartment, suite, or unit number.
Or maybe we didn’t get the memo on the mailing protocol.
1
l
The first is the number one the second the letter L. That’s why.
My old address used to just be 1 Streetname Circle. I would always put 1. The people I lived with would constantly say #1 when giving direction or witting it down and it would drive me crazy. I told them they were wrong, and as an added bonus that their blood was not really blue. They wouldn’t have any of my nonsense.