Thanks for that. Seemed a very decent guess there is a business relationship between Zeiss and the forum. Do you know more? Why just Zeiss? Or nature of the arrangement? Is “Official” a named thing?Zeiss is the official sponsor of Birdforum. It's fairly obvious; that's why there's a ZEISS tab at the top of the page, the Zeiss section is at the top of the list, etc. There must be a significant cost to running this forum, though other ads must also help.