The new ACUX includes a string "Can't see the image? <link>Request an account</link>", forcing any MediaWiki instance to have such page and such process in place. English Wikipedia does have it but e.g. as far as I know mediawiki.org doesn't, just like most MediaWiki projects out there.
Forcing MediaWiki projects to have that process if they want to use captchas for registration is not the way to go. This string should be optional. Or it could be simply removed from the extension itself, allowing admins to add it as part of whatever text they want to edit / hardcode in the user creation page.
Also note that, for consistency,
Bug 4845 - CAPTCHA doesn't work for blind people
was open in 2006 and currently has Low priority. Either we think this is an important problem (and we try to fix it with audio captcha or some post-captcha system) or then we don't push the ugly patch (a parallel manual process) so aggressively to all MediaWikis by default.
Version: 1.22.0
Severity: normal
See Also: T6845: CAPTCHA doesn't work for people with visual impairments