HTTP Request Headers If-Modified-Since Referer User-Agent
{"Image DocumentName": "HTTP Request Headers If-Modified-Since Referer User-Agent", "Image ImageDescription": "Indicates client wants page only if it has been changed after specified date. Don\u2019t handle this situation directly; implement getLastModified instead. Referer. URL of referring Web page. Useful for tracking traffic; logged by many servers. User-Agent. String identifying the browser making the request.", "Image XResolution": "37", "Image YResolution": "37", "Image ResolutionUnit": "Pixels/Centimeter", "Image Software": "SlidePlayer", "Image YCbCrPositioning": "Centered"}