Script navigation

   Sometimes scripts are used for site navigation. As a a SEO worker, you need to understand that search engines can not read or execute scripts. Thus, a link specified with the help of a script will not be available to the search engine robot will not follow it and so parts of your site will not be indexed. If you use site navigation scripts then you must provide copies of the regular HTML to make them visible to everyone - your human visitors and search robots.

      Session Identifier
 
Some countries use the session identifier. This means that every visitor gets a unique parameter (& session_id =) when he or she arrives at the site. This ID is added to the address of every site visited in the country. Session ID help site owners to collect useful statistics, including information about the behavior of visitors. However, from the point of view of a robot, a site with a new address is a brand new. This means that, every search robot comes to such a place, he will get a new session identifier and will consider the pages as new ones whenever it visits them.

   Search engines have algorithms for consolidating mirrors and pages with the same content. Sites with session IDs should, therefore, be recognized and indexed correctly. However, it is difficult to index such sites and sometimes they can be indexed incorrectly, which has a negative effect on SEO rankings page. If you are interested in SEO for your website, I recommend you avoid session identifiers if possible.

    follow
 
Redirects make site analysis more difficult for search robots, with resulting negative effects on SEO. Do not use redirects unless there is a clear reason to do so.

    Hidden text, a deceptive method SEO
 
The last two issues are not really mistakes but deliberate attempt to deceive search engines using illegal SEO methods. Hidden text (when text color matches the background color, for example) allows site owners to fill a page with their desired keywords without affecting page logic or visual layout. Such text is invisible to human visitors but will be seen by search robots. The use of such deceptive optimization methods may result in banning of the site. This can be excluded from the index (database) search engine.