After you have chosen your desired flight from the result list, you can click on "details". Here you will find the different available fare options for your flight in the drop-down-menu.
Below the drop-down menu you are shown the relevant symbols for your chosen fare.
The following symbols are available:
Further information can be found by moving the cursor over the respective symbol.
These symbols are already available for the most frequently booked airlines like LH-Group, EasyJet, Eurowings. Further carriers will follow in the coming weeks.