The anchored text box is just like a standard text box except that it is anchored to the screen. What this means is that the anchored text box will stay visible on the chart and doesn't scroll with a series, no matter how far into the past or future you scroll the chart:
All options available for Anchored text appearance may be set in Style properties dialog:
Where the text is typed.
Toggles the visibility, color and opacity of a background for the text box.
Toggles the visibility of a border for the text box. Can also change the border color.
Enables/Disables text wrap within the text box.
In Visibility properties dialog you can switch displaying of Anchored Text for charts of different timeframes.