Archive Links is a feature in the link shortener to archive links, links that are automatically archived cannot be accessed by other users (links go to 404 Not found).
Link plus is used to find out the original link with the s.id symbol. The link plus feature is also used to determine whether the link is in the form of a microsite or a shortener link.
Every time the s.id link leads to a page that says "Link Expired", then the s.id link is no longer accessible because the time previously set by the link owner has expired.