Cameras are more and more packed with options, many are also sophisticated, but the manual (and the online help) often doesn't contain anything more than the setting name, just reworded in a complete statement, but without providing further information. For instance:
Phase Detect. Area
Sets whether or not to display the Phase Detection AF area.
MENU →
(Focus) → [Focus Area] → [Phase Detect. Area] → desired setting.
Menu item details
On😃isplays the Phase Detection AF area.
Off😃oes not display the Phase Detection AF area.
LOL. A short paragraph follows about the fact that not all lenses support this feature, but nothing more. At least a picture with the lookout of the display would be fine (I had to search through the internet to find a screenshot, it's a pair of brackets) and possibly a hint about how to use the feature in practice would be welcome.