Represents a reference entity. Reference is a link from one article to another. When an article that's being imported contains a link to another article, this link is imported as a temporary string at first. This approach ensures that links to articles that are not imported yet are not lost. When import is finished, temporary strings are replaced with ordinary references to existing articles when possible.
The type of document in YouTrack where the reference points to. The expected value is `page`.
The URL of the linked article. If the linked article is not imported for some reason, this URL will be shown instead of a link.
The ID of the linked document.
The temporary reference string. When import is finished, this string will be replaced with a link to a real article.
The type of the custom field.