and golang url parser chokes on that, saying it's invalid percent encoding. Now, you want to know which fuck fucked it up. and fuck the programer fucks in industry.
note, probably ecma is incorrect there. also, url percent encoding spec is extremely complex. browser don't agree on it. the spec is prob wrong too.
imagine, a doc from standard org creates invalid doc. Note, back then, all docs of w3c or RFC are invalid html. you can see stories at History of Web Tech and Anti Hacker y2k Anti Hacker y2k