How to hide a page from search engines?

Question

Search Engine Optimization

I am creating a service page. How can I make search engines not see it at all?
What if there were no links to it anywhere on the site?
That is, as I understand it, if you create a file.txt in the root directory, say, then the page will be available only at the direct address site.ru/file.txt, but search engines cannot find out about it unless they are directly informed (something like “re-bypassing pages in Yandex)
If the page is created by a separate template, then how to achieve the same result?

Answer 1

I would add a rule like Disallow: /file.txt to robots.txt. For a paranoid level of protection against indexing, I would also add .htpassword to the opening of this file.