I need to be able to validate BTC addresses. I keep reading how characters 0, O, I, l are not allowed to avoid visual ambiguity.
That said, I've run into a couple of address which contain these characters, and they seem to be fine:
bc1qar0srrr7xfkvy5l643lydnw9re59gtzzwf5mdq
bc1qvtrafpjnl3ygg2w40eldlq7ggdgg8wuu3nqcxe
So what's going on with these? Do these rules not apply to bc1 address? Are they more of a recommendation than a requirement? Thanks