Bookmarking is when the browser remember the URL of a page. GETs can be bookmarked because the data needed for the request is stored in the URL and hence the bookmark. POSTS cannot because the data is stored in the request body which is not stored as part of the bookmark.
You cannot use your browser to bookmark a POST request, but you can use HTTP sniffers to get the request/cookies.... and store them to use them back again later. There's one in NetbeansIDE. I think it was called HTTP Monitor.