This is a policy, most notably in Chicago , that requires certain residential developments to include affordable housing units or contribute to a housing fund.
This is a high-compression archive format that bundles multiple files into one small container. It is widely used because it can reduce file sizes by 30-70% more effectively than the standard ZIP format. How to Open "aro.7z" aro.7z
Since .7z is not natively supported by all operating systems, you will need a third-party tool: This is a policy, most notably in Chicago