https://github.com/jayvdb/https-everywhere-py/blob/a3f2b42/https_everywhere/_rules.py#L406 There are lots of cases of regex which refer to hosts which are not in the rule targets. They are currently detected, but are not being rejected, or considered in the tests. The known ones are stored in [`_FIXME_BROKEN_REGEX_MATCHES`](https://github.com/jayvdb/https-everywhere-py/blob/a3f2b42/https_everywhere/_fixme.py): ```py _FIXME_BROKEN_REGEX_MATCHES = [ "affili.de", "www.belgium.indymedia.org", "m.aljazeera.com", "atms00.alicdn.com", "i06.c.aliimg.com", "allianz-fuercybersicherheit.de", "statics0.beauteprivee.fr", "support.bulletproofexec.com", "wwwimage0.cbsstatic.com", "cdn0.colocationamerica.com", "www.login.dtcc.edu", "ejunkie.com", "e-rewards.com", "member.eurexchange.com", "4exhale.org", "na0.www.gartner.com", "blog.girlscouts.org", "lh0.google.*", # fixme "nardikt.org", ".instellaplatform.com", "m.w.kuruc.org", "search.microsoft.com", "static.millenniumseating.com", "watchdog.mycomputer.com", "a0.ec-images.myspacecdn.com", "a0.mzstatic.com", "my.netline.com", "img.e-nls.com", "x.discover.oceaniacruises.com", "www.data.phishtank.com", "p00.qhimg.com", "webassetsk.scea.com", "s00.sinaimg.cn", "mosr.sk", "sofurryfiles.com", "asset-g.soupcdn.com", "cdn00.sure-assist.com", "www.svenskaspel.se", "mail.telecom.sk", "s4.thejournal.ie", "my.wpi.edu", "stec-t*.xhcdn.com", # fixme "www.*.yandex.st", # fixme "s4.jrnl.ie", "b2.raptrcdn.com", "admin.neobookings.com", "webmail.vipserv.org", "ak0.polyvoreimg.com", "cdn.fora.tv", "cdn.vbseo.com", "edge.alluremedia.com", "secure.trustedreviews.com", "icmail.net", "www.myftp.utechsoft.com", "research-store.com", "app.sirportly.com", "ec7.images-amazon.com", "help.npo.nl", "css.palcdn.com", "legacy.pgi.com", "my.btwifi.co.uk", "orders.gigenetcloud.com", "owa.space2u.com", "payment-solutions.entropay.com", "static.vce.com", "itpol.dk", "orionmagazine.com", # fix merged, not distributed "citymail.com", "mvg-mobile.de", "inchinashop.com", "www.whispergifts", # already merged? "css.bzimages.com", "cdn0.spiegel.de", ] ``` These are mostly fixed in https://github.com/EFForg/https-everywhere/pull/18949 and https://github.com/EFForg/https-everywhere/pull/18957 , but upstream has difficulty reviewing complex changesets - splitting them might help, but even so the progress on smaller PRs is very slow, so these problems will linger for a while, and need to be fixed in this library. The regex hosts need to either be tested properly so that the extra hosts can be added to the targets and so be used in the processing logic, and optimised sanely, or the regex should be simplified to remove these extra hosts.