HTTP Compression
The <httpCompression> element specifies the HTTP compression settings for Internet Information Services (IIS) 7. HTTP compression can provide faster transmission times between IIS and client browsers that can accept compressed files.

Note: An HTTP client must initiate communication for compressed content by sending the appropriate HTTP Accept-encoding header. If a client is not capable of HTTP compression, it will not pass that header and IIS 7 will always return uncompressed content.

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