PNG is a file format for raster images with lossless source coding of the encoded image data. Its first W3C Recommendation, dated 1 October 1996, described a portable replacement for earlier image formats; this situates the design in exchanging images reliably between systems.[ref]
https://www.w3.org/TR/REC-png-961001. W3C, PNG (Portable Network Graphics) Specification, 1 October 1996, status and abstract
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