Excerpt from my notes when I was deciding on a link syntax for my own lightweight markup language:

AsciiDoc doesn’t actually have a real link syntax—what it has is more or less an natural consequence of other syntax choices, but isn’t actually URL-aware, and will mangle some less common URLs. Still, what you get is mostly this kind of thing:

• https://example.com[Link text]

• link:URL[Link text]

But woe betide you if you go beyond what it supports, its techniques when you need escaping are grotesque, monstrous horrors. Seriously, when you fall off the happy path, AsciiDoc is awful.