What does this icon mean in iPhone?

Question

iPhone

Recently, a new icon appeared in the iPhone. Who knows what it means?

Answer 1

This icon indicates that Teletype (TTY) mode is enabled.
... This mode is intended for people with hearing and speech disabilities...
Here is a description of the system icons, and for example, here is a description of the icons in Russian.

Answer 2

Thank you. And what does the circle mean, which from time to time appears after the inscription Beeline? Somehow not all status icons are indicated there.