fyi see the doc in https://developer.matomo.org/guides/tracking-javascript-guide#optional-creating-a-custom-opt-out-form

See docs

         * Calling this method will remove any previously given consent and during this page view no request

         * will be sent anymore ({@link requireConsent()}) will be called automatically to ensure the removed
         * consent will be enforced. You may call this method if the user removes consent manually, or if you
         * want to re-ask for consent after a specific time period.

that should be on purpose only during this page view or not?

@tsteur In that case I (and the help at https://developer.matomo.org/guides/tracking-javascript-guide#optional-creating-a-custom-opt-out-form) are misunderstanding the use case for that feature.

I was recommending to use optUserOut to people who had issues as their Matomo is on a different and therefore the opt-out iFrame isn't working as most browsers block third-party-cookies.
Also for people who wanted to customize the look of their opt-out more than it is possible with an iFrame.

The docs for optUserOut also seem to indicate this use case:

@Findus23 I don't really know how it is supposed to be used for user opt outs. The initial implementation was for consent and then some symlinks for userOptOut and forgetUserOptOut was added. Not sure how much these actually work. Maybe it was misunderstood how these methods behave when adding the symlinks.

For a custom opt out they can't really work I think since you would also need to "requireConsent" on every page load or so? Not sure.

@Findus23 is this issue maybe then only about updating the docs?

I’ve been trying to use this feature to create a custom opt-out form, because the one built into Matomo doesn’t work if you’re tracking sites over multiple domains (third-party cookie blockers are on by default in a few browsers now). If this cookie is a misunderstanding of the use case, perhaps the function shouldn’t be called “optUserOut” and the docs should be updated, and whatever opt-out cookie the built-in opt-out form sets should be exposed to users. My main issue at the moment is I have no reliable way for a user to opt out of tracking. Please excuse my ignorance if any of this is wrong, I’m a Matomo user and I’ve not contributed to the Matomo project before.

Looking at this PR 6f5b85b#diff-1279d666063b65e6d6777f902d11574fR7302 it was maybe meant to be stored forever the cookie? Or what life time should we set here? From what I see we would need to set like year 2030 as it can't be stored forever. If we can make this use case work by fixing the set cookie to store it forever, I reckon we should.

Mozilla actually suggests setting document.cookie = "someCookieName=true; expires=Fri, 31 Dec 9999 23:59:59 GMT"; :) https://developer.mozilla.org/en-US/docs/Web/API/document/cookie