Why should I set a priority for the Gzip and Deflate Compression Schemes?
Certain resource requests from browsers might contain both schemes in the Accept-Encoding header that defines what type of encoded or compressed content the browser can accept and decompress. IIS 6.0 built-in compression determines which compression scheme to use when compressing a response by choosing the scheme with the highest priority. You can manage the priority of Gzip and Deflate compression schemes in ZipEnable by selecting Settings > Global > Advanced Settings and then the Compression Schemes tab.