I found from hard way that lemmy community urls are bit problematic. Here is the story, which contains bit NSFW material.
I was trying to figure out in Jerboa how to subscribe to community in another instance. First one that I came across, that i was not subscribed to was !hairypussy@pornlemmy. com. (I know, I know, I am a perv)
I copy pasted the community path to my android clipboard, and tried few ways in the app, and eventually gave up.
Some time passes, until I went to do some shopping. My wife and I use a shared shopping list. From this shopping list I found this beatiful community path.
My wife had a laugh, but I was worried that If she would have been bit more jelous side, she could have made a assumption from the structure of the path.
The thing is that !hairypussy @ pornlemmy. com looks like email address. This could have been misunderstood quuuite badly.
I am a coder also, so @ is sensible separator, and serves the same purpose as in email. Probably it should not change, but the structure can cause misunderstandings with some communities and lemmy instance urls. Of course here main issue is user error, and any link to some bad site can be issue, but people understand what website URL is.
Please let me know if this needs NSFW tag.
but these solutions would not have saved my clumsy ass in the original case.
If instance would have been fictional furryporn.com and community is called worldnews, and I sent to my grandmother a message containing community url !worldnews@furryporn.com, it would not really matter is it in form of c/worldnews@furryporn.com or with !