Here the task is to transfer unique form data in the current tab, which are not transferred by the get method, so that the same address in another tab does not receive them when the page is refreshed. Cookies are obviously not suitable here, since they work on this address in all tabs. I had a similar problem when I started using history.pushstate and discovered that it deletes the post data transferred for the page and refreshing gives the result of a get request without parameters.