Under this definition fall the common hotels data, the definitions of:

• treatment (“room only” rather than "bed and breakfast")
• breakfast (“continental” rather than “ American”)
• categories (“tourist” or “superior”)
• descriptions (“modern” rather than “traditional”)

and - essential for proper management of the availability - of what we call in Towers “contract type”, that ranges from the most common types of contract (standard, deluxe, executive, etc ...) up to the more exotic related to specific hotels with their specific nomenclature.