HTML form controls now support the "autocomplete" attribute so browsers might manage and propose autofill: https://html.spec.whatwg.org/multipage/form-control-infrastructure.html#autofilling-form-controls:-the-autocomplete-attribute:attr-form-autocomplete
 
The "autocomplete" attribute could be added to XForms Specifications as in HTML.
 
When evaluating it for XSLTForms, it appears that an embedding HTML "form" element is required (which can be automatically added by XSLTForms).
 
For credentials, there is a Javascript API to propose to store the credential which was typed with an HTML form (https://developer.mozilla.org/fr/docs/Web/API/PasswordCredential and https://whatwebcando.today/credentials.html). I have not found a Javascript API yet to store other values but it is possible to store them manually. After that, autofill works great.
 
What do you think?
 
Regards,
 
--Alain