Meanings of underdot in English

The red dot below the screen.

The dots below, Bert saw, were not running now, but standing and looking up.

The multi-posts are denoted by a small icon and a series of blue dots below the first image.

Broad "a" (two dots below) is taught by recalling the familiar phonogram "all" and the series: ball, fall, call, tall, small, etc., pronounced.