As regards hotel rooms, there are several different service types and you can use this text field to make your own selection.
We recommend this filter for advanced users, because basic service can be ussually changed additonally (reduce or enlarge amount provided services).
You can use for example following strings:

• "Room only" = only rooms/hotels with basic service "room only" but ussually you can add breakfast or more.
• "breakfast" = only rooms/hotels with basic service including "breakfast", but ussually you can add halfboar or fullboard etc.
• "treatment" = only rooms/hotels with basic service including "treatment", eg. Fullboard and treatment, or halfboard and treatment
• Etc.