How to publish a link to a private channel in telegram?

Question

Telegram

Hello. I have a private channel in telegram. According to the telegram rules, I can post +18 pictures there, since this is a private channel and the link to the channel is not publicly available. However, it is not entirely clear what "public" means. For example, I see how in many open channels I make links to closed channels in which there is a lot of porn and +18, and isn't this considered public? Can you explain this question in as much detail as possible. Let's say where exactly they will check whether it is publicly available or not. Can I give this link offline to people or on other sites, can I show this link to subscribers in another open channel or only in private messages? Explain please.
Here is a clipping of the rules from the telegram
. What content is prohibited from publishing in channels?
In public channels, it is forbidden to publish illegal content, due to which Telegram can be blocked in Apple and Google stores. Such content includes porn, erotica, pirated music and files, etc.
There are no such restrictions for private channels (provided that the link to such a channel is not publicly available).
Channels related to ISIS and terrorist propaganda will be blocked regardless of the policy of Apple and Google.