Cancelling out of HTML5 browser validations !
This post is based on a short scary movie, I was working on a cool HTML-5 page
<apex:page .... docType="html-5.0"/>
But all the coolness disappeared when powers of CANCEL button are gone. The typical Cancel button in salesforce, which is always tough enough to get out of any validation, i.e.
<apex:commandButton action="{!cancel}" value="Cancel" immediate="true" />
Read More: https://abhinav.fyi/cancelling-out-of-html5-browser-validations/