The most useful META - tegi which will help poiskovikam to index pages of your site correctly:

1. Or - management of indexation of pages for search robots. In this case, specifies to the search robot that he did not index all pages.

2. - it is necessary for search engines, whether to define  the page to the given search is relevant.

3. - raises probability of a presence{finding} of page poiskovikom on the chosen search (am).

4. - management of indexation of page for search robots. Defines{determines} frequency of indexation. In this case it is underlined, that your document is dynamical and the robot should index it  on a regular basis.

Is tegi which it is direct to indexation do not concern, but carry out also the important role dl convenience of job of the user with a site:

1. - the control of caching for HTTP/1.0. does not allow kehshirovat` pages.

2. - definition of a delay in seconds after which the browser automatically updates the document or occurs a redirect.

3. - specifies, when the information on the document will become outdated, and the browser should take a new copy, instead of load from a cache.

There is one more meta-teg revisit-after, concerning use which many hearings went earlier, that he can force to visit{attend} robots of search engines a site with the certain periodicity, however experts a Yandex have officially denied it.

There is no guarantee, that search engines take into account contents meta-tegov, indexing a site. Especially there is no guarantee, that this information will be taken into account at ranging a site in delivery. But meta-tegi are useful to those, that at indexation of pages allow poiskovikam to receive the necessary information on a resource.

To register them a lot of time, therefore is not necessary try to enter maximum full metainformation about page.

Problems at indexation of pages

Working in sphere of search promotion of sites, it is necessary to face problems of indexing of sites search engines, time "losses" of some pages of sites, and, as consequence{investigation}, loss of positions on keywords. There is it, in overwhelming majority of cases, because of mistakes of web designers. In fact it is far from being everyone understand, that, at first sight, even the insignificant mistake or omission can lead to to "significant" consequences - to loss of positions in delivery of search engines. Further the list of problems which you can collide{face} at indexation will be considered.

3.1 Dynamic pages, identifiers of sessions.

Problem. The robot of the search engine receives the same page with different identifiers of sessions. The search engine "sees" it as different pages. Too most occurs and to dynamic pages.

The description. On some sites there are dynamic pages with the various order of parameters, for example index.php? id=3*show=for_print and index.php? show=for_print*id=3. For users is same page, and for search engines - pages different. Also it is possible to give an example with page of a site: « the version for a seal » with the address, for example index.htm? do=print and the most important page index.htm. On structure and text filling these pages are practically identical. However for the search engine are different pages which "will be stuck together", and, instead of, for example, advanced{moved ahead} main page in delivery poiskovika there will be a page « for a seal ».

The similar problem arises at use, by default, links to a directory and to a file in a directory, for example/root/and/root/index.htm. For users she is solved use of the directive « DirectoryIndex/index.htm » a file .htaccess, or adjustments of the server. Search machines solve the given problem: eventually "stick together" index page with "root" of a directory.

One of kinds of dynamic pages - pages with identifiers of sessions. On sites where it is accepted to use identifiers of sessions, each visitor at call on a resource receives unique parameter *session_id =. It paramet is added to the address of each visited{attended} page of a site. Use of the identifier of session provides more convenient gathering statistics about behaviour of visitors of a site. The mechanism of sessions allows to save the information on the user at transition from one page of a site to another that does not allow to do{make} report HTTP. The identifier is stored{kept} at the user in kuki or added as parameter to address of page.

However, as robots of search engines do not accept kuki, the identifier of session is added to address of page, thus the robot can find a plenty of copies of the same page with different identifiers of sessions. Easier speaking, for the search robot the page with the new address is a new page, at each call on a site, the robot will receive the new identifier of session, and, visiting{attending} the same pages, as earlier, will perceive them as new pages of a site.

It is known, that search engines have algorithms "sklejki" pages with the identical maintenance{contents}, therefore the sites using identifiers of sessions, nevertheless will be proindeksirovany. However indexation of such sites is complicated. In some cases she can pass incorrectly, therefore use on a site of identifiers of sessions is not recommended.

The decision.

As to dynamic pages it is necessary to close pages « the version for a seal » and other duplicates in a file robots.txt, or with the help of attribute meta-tega noindex. Other decision - beforehand to create funkcional a site which would not generate dynamic pages with the various order of parameters.

As to identifiers of sessions the decision of the given problem idle time - to register with .htaccess the following commands:

php_flag session.use_trans_sid Off

php_flag session.use_only_cookie On

php_flag session.auto_start On

3.2 Incorrect processing 404 statuses

Problem. Mistakes in processing 404 statuses the server when instead of 404 codes (the page does not exist), the server gives a code 200 and standard page of a mistake.

The description. To process 404 mistake it is possible differently, but the sense remains one. The basic and most simple variant of processing of the given mistake - creation of page, for example 404.htm and recording in a file .htaccess « ErrorDocument 404/404.htm ». However so all act not the web designer, many adjust the server to delivery of the main page of a site at 404 mistake. Here that "reef" also is hidden. In case of incorrect adjustments of the server, for page with a mistake 404 (i.e. in this case given main), the server returns 200 OK. Thus, it is possible to receive the absolute{hundred-percent} duplicate of the main page owing to what the robot poiskovika can "stick together" her  with any other page of a site.

The decision. The output{exit} from the given problem is those: competent adjustment of the server and processing 404 codes through a file .htaccess by creation of separate page under processing of a mistake.

3.3 Plagiarism

Problem. Accommodation of materials of a site on other sites, and, as consequence{investigation}, - "pasting" and loss of positions.

The description. The description of the given problem is made in its  name, and in the modern Internet all is well-known, that plagiarism is "larceny" of a content and "giving" of copyrights, and, from the point of view of search optimization, is also problems with indexation of a site as occurrence of takes of his  pages.

The decision. The decision of a problem here one - the letter with the complaint about infringement of copyrights, khosteru the site - plagiarist, preliminary having warned, certainly, guilty that he acts illegally.

3.4 Other problems

Neindeksacija some elements of page can be called by the several reasons:

1. The text is made in teg. It is special teg, forbidding indexation of the text to the robot of a Yandex.

2. The text is located in a script, t.e between tegami

3. The text is located in comments

4. Very small size of page (the Yandex does not index files less than 1 kb)

5. The resource does not contain Russian text (besides, it concerning to a Yandex)