Carriage of bicycles on Hungarian trains

I am planning a cycling trip in Hungary, but train travel is the only option for some parts of my trip. Luckily, I can take my bike on board some of the (slower) trains. If you plan your journey using Elvira (e.g. from Budapest to Tokaj) and tick the box "carriage of bicycles", then for some trains you get a small bicycle sign in the comments section on the right. What exactly does this bicycle sign mean? Is carriage of bikes only allowed on trains indicated with that bicycle sign or do the trains indicated with that bicycle sign have special compartments for bikes or perhaps something else?