#TIL the query component of a URI is actually completely opaque. There is no such thing as a "query parameter" defined in any spec that I can find -- the use of ampersands to delimit such "parameters" is purely conventional!
At some point (HTML4), the recommendation was to use *semicolons* instead: https://www.w3.org/TR/html4/appendix/notes.html#h-B.2.2
There is even a line of argument that says that query parameters are a misfeature and antipattern. Any "parameter" should be passed along with the request itself, not the URI