> On March 1990 they published the document RFC1060 (https://www.rfc-editor.org/rfc/rfc1060 https://www.rfc-editor.org/rfc/rfc1060) where they listed the well-k

> On March 1990 they published the document RFC1060 (https://www.rfc-editor.org/rfc/rfc1060 https://www.rfc-editor.org/rfc/rfc1060) where they listed the well-known ports at that time. In that list there wasn't a protocol assigned to port 80. It went from 79 to 81: 79 FINGER Finger 81 HOSTS2-NS HOSTS2 Name Server > So, at that time port 80 was officially free. > In 1991 Tim Berners-Lee issued the first version of HTTP in a document about HTTP 0.9 (http://www.w3.org/Protocols/HTTP/AsImplemented.html http://www.w3.org/Protocols/HTTP/AsImplemented.html) where he stated: >> If the port number is not specified, 80 is always assumed for HTTP. > Then in July 1992 was published RFC 1340 that obsoletes RFC 1060 (https://www.rfc-editor.org/rfc/rfc1340 https://www.rfc-editor.org/rfc/rfc1340) where appears: finger 79/tcp Finger finger 79/udp Finger www 80/tcp World Wide Web HTTP www 80/udp World Wide Web HTTP > That document makes official the port 80 as www or http. [...] From https://superuser.com/a/996843 https://superuser.com/a/996843 So at 1994, 80 is pretty much the default, but sometimes it was specified anyways, just like some addresses you see around still prints/shows http:// http:// / https:// https://. Not everyone know what part of the URI is important or not.