In fact : it's not a feature request : really don't know what core must do.

Maybe best choice is :

• use alert and confirm function
• let template manager update this js function if he want (do it in default template)
  => Then we can just add a array of some language string : needed : Yes/No/Close/(Cancel ?)/(Confirm ?)

Currently I would vote for "let template manager update this js function".

I still don't know why alert system is default.
These popups save reload time, but since browser can offer to suppress alerts I never go for them. Are there big fans of the alert system? I can remember a time where showpopups=0 was the default setting in LS.

In LS 2.5 the showpopups=0 scope won't prevent dialogs in JS in certain situations, right? Cause I never saw a yes/no/cancel/confirm dialog inside html.
A info/alert box above the first question with html dialog would be my favor.
No javascript popup/alerts. But there must be a reason, why alert js is there.

confirm is used for Clear all button only actually.

alert can be easily replaced in template : default template do it, but we can easily replace by a div at start of survey.

alert is used when come back to a survey : if you don't answer a mandatory question for example.

Maybe add some "langage string tool" :)

Fixed in https://bugs.limesurvey.org/view.php?id=11970

core package use alert/confirm in a new function. template-default package update this function, template.js can update this function.