Key:mattress

mattress=* indicates whether a feature provides a  Mattress
It may apply to a

• tourism=wilderness_hut
• tourism=alpine_hut
• tourism=hostel

Mattresses types

In case you'd like to further specify it, you may use other values instead of yes, examples

•  Mattress - mattress=* foam/spring
•  Futon - mattress=* cotton
• mattress=* sleeping_mat

See also

• beds=*
• rooms=*
• capacity=*