Kartris is designed to run on a single domain. If multiple domains are mapped to the same web, Kartris will 301-redirect any requests to the domain set in the general.webshopurl config setting. This helps channel page rank and links towards the preferred domain.

For example, many sites have both domain.xyz and www.domain.xyz pointing to their site. Kartris will redirect to the preferred one of these if someone uses the other one where necessary. While this has no real impact from an SEO point of view (there really aren't the duplicate content issues as we'll cover later), it does ensure that all users are using the same domain always, which is important for cookies