Currently, if you make screenshots ingame (default key: F10) they will be saved in Documents\ManiaPlanet\ScreenShots, like you can see on the following picture:

The names are just "ScreenShot01", "ScreenShot02" and so on. The problem I see there is, that you can only create 99 screenshots. And the name of the screenshot doesnt give any relevant Information.
My Suggestion: Give them other names.
Android for example saves the pictures you make with your smartphone with following naming convention: IMG_date_time
Example: IMG_20180630_133031
This means, picture was created today (30.06.2018) at 13:30:31
Why not using a convention like this? Would be much easier to read and store Screenshots
