How to correctly specify host and sitemap in robots.txt?

Question

Search Engine Optimization

Hello, on different large sites I observe different options for placing the hosts and sitemap directives.
Tell me, having settings for different robots in the form:
User-agent: Yandex
User-agent: Googlebot
User-agent: *
Where to insert Sitemap and Hosts - into each, or only one or through the line?

Answer 1

It doesn't matter at all. In the webmaster panels, specify which version of the site is considered the main version and where the sitemap is located.
I will reveal a couple of secrets:
1. host has been deprecated a long time ago
2. If the site is well made, then the site map is not really needed