Using tab index attribute in HTML form fields a user can easily navigate to the next or previous field by merely using the keyboard. But after some presses, Tab index focus caret secretly goes to a new dimension where it becomes impossible to press tab to get back that caret guy in place. ultimately we use to move back caret guy in place.
So during a requirement where I wanted to trap carret guy in a wrapper so that even after continous tabbing caret we never be able to leave that defined wrapper. After defined at input field that will focus on first defined form field automatically.