Multiple anchors at the same URL breaks definition lookup panel
mimesniff has normative references to multiple ABNF productions in HTTP RFCs. However, because of the way the IETF website is set up, the links can only get as close to the appropriate section of the RFC, which can result in multiple definitions linking to the same URL.
It seems that this breaks the definition lookup panel for anything but the first term, as the name has been suffixed in such a way that has apparently not been carried through to the whole document.
For example: https://mimesniff.spec.whatwg.org/commit-snapshots/9507947f29584a34a3393d518cdaf77682ac5a23/#index-defined-elsewhere
Here clicking on "quoted-string" as defined in [HTTP] brings up the lookup panel just fine, but clicking on "token" does nothing and displays an error in the console:
Couldn't find .dfn-panel[data-for='term-for-section-3.2.6①']
Oh, it looks like the use of the second term is actually getting grouped in with the use of the first term, so technically both definition lookup panels are broken.