There is clear signage of sustainability certifications.

What’s the impact: Accredited sustainability certifications are a clear sign that the company has started its sustainable journey. (1) & (2) & (3)

Parameter applicable for: Accommodations, Places to eat and drink, Shops 

If a company has accredited sustainability certifications it means that it is, first of all, interested enough in sustainability to have reached out to a third party for certification and that it has some sustainability practices that allow it to claim that certification.