In the past you could set up meta tags for search terms in the head. This looked like this in the source code:
<meta name="keywords" content="Für, diese, Keywords, möchte, ich, ranken">
At the request of our users, we still have the dialog for this in the system. You can find it under "Options" on the left in the main menu, then again on "Options" and then in the SEO section as the second menu item:
In addition to the search terms, you can also enter the "meta tag" for the author of your website. This makes sense. If you enter search terms, please separate each term with a comma.
Google ignores since at least 2009 all search terms that are stored as "meta tag" completely. So you will have no improvement in ranking, no matter how many keywords you enter here. You can save yourself the trouble. Make sure that the content of your website contains relevant keywords.
in the video below, Matt Cutts of Google clearly states, "We don't use the keywords meta tag for ranking...there's just been too much spam with it. We don't use that information."