How is the formation of full-text RSS in the format for export to Google Publisher Center?

In addition to standard RSS 2.0 elements, the special element "content:encoded" is required to export data to Google Publisher Center, which contains the full contents of the publication:
    <content:encoded>Full contents of the publication</content:encoded>

To include the full content of publications, the feed must use the additional namespace:
HTML will be placed in the CDATA section.
Our robot extracts the full text of publications on web pages using a special algorithm, as well as on pages marked with markup (supported types: Article, NewsArticle, BlogPosting, LiveBlogPosting).