These are some key concepts one must learn on its life-long learning journey.
As personal cherry-picks, these concepts exemplify the intricacies outlined in the ever-growing collection of RFCs (the number is set to surpass 10 000 by next year). Understanding these ABCs will smooth the path to one’s next practical application.
I had a dream about the next bullet/point (D).
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Well-Known URIs
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References:
https://www.rfc-editor.org/rfc/rfc8615.html
https://www.iana.org/assignments/well-known-uris/well-known-uris.xhtml
https://well-known.dev