While no good SEO would recommend spending any time on this tag, there’s a small chance it will be helpful to you somewhere. If you’re building a site, omit it, but if it’s automated, there’s no reason to remove it.
Refresh - This is a poor man's redirect and should not be used if at all possible. You should always use a server side 301 redirect . I know now sometimes things need to happen but Google doesn't like it .
Site Verification - Your site is verified by Google and Bing, right? Who has the verification meta tag on their homepage? These are sometimes necessary because you can't load other forms of site verification, but if possible, try to verify another way. Google allows you to verify via DNS, an external file, or by linking your Google Analytics account. Bing still only allows XML files or meta tags, so use that if you can.
Bad meta tags
Nothing bad will happen to your site if you use these - let me make that clear. They are a waste of space, though. If you're ready and willing, maybe it's time to do some spring cleaning of your <head> area.
AuthorWeb Author - This tag is used to name the author thailand mobile database of the page. It just doesn't have to be on the page.
Return visit – This meta tag is a command for the robot to return to the page after a certain period of time.
Rating - This tag is used to indicate the maturity rating of the content. I wrote a post about how pages with adult images were marked using a very confusing system that was later updated see the comments on the post. The best way to document bad images is to put them in a directory separate from the other images on your site and alert Google.
ExpirationDate - "Expiration" is used to record when the page expires, and "Date" is the date the page was created. Are any of your pages about to expire? If so, just delete them but don't update the content, or even the contest - make it an annual contest instead!. For "Date", make an XML sitemap and keep it up to date. This is much more useful.