Comment by ninjaoxygen

True, it has never been in an HTML standard, however it was definitely a documented part of early HTML.

The blink element was in Netscape Navigator's HTML dialect in 1993/94, when early HTML was still just hitting IETF RFCs / DRAFTs, you can find blink in the Netscape HTML developer documentation from just after that era, DevEdge. It was never in NCSA Mosaic, the other big GUI browser of the era.

Later on in the process of being standardized, when it was more W3C than IETF albeit still mainly the same people, Netscape agreed to drop blink from the proposals if Microsoft dropped marquee, so in that sense yes, it was never in a standardized version of HTML, but many tags in active use at the time were never in a standards doc.

See here https://www.w3.org/People/Raggett/book4/ch02.html for some history from w3c, who went on to become the formal custodians of HTML after the IETF days.

Edit: here's the earliest Netscape Developer Docs I can see on archive.org https://web.archive.org/web/19961115043739/http://developer....