Meta tags (meta tags) is a very useful label, it is located in the head of the document storage, some pages of information, the most common is description and keywords, they were told what is the search engine, page description and keywords. Use the following:
: you can crawl the page.
NOFOLLOW command: tell search engines to find links, refused to allow access from this page.
HTTP-EQUIV is used to provide some information to the browser, according to these instructions accordingly. HTTP-EQUIV is not only a function of this character encoding ", commonly used HTTP-EQUIV type also includes:" the expiration time, the default script language, the default page style language, auto refresh time.