1.I used the auto-sitemap-generation website to generate my sitemap but I found that two many useless items such as "bank of bbs","add a post" etc in it. Do I need to delete all these items and just leave the posts links in it? 2.After I submit my sitemap once, do I need to update it from time to time? Suppose I have a bbs and the posts increase everyday but these new posts are not included in the sitemap.