Have recently had 3 of my listings been marked as having outside links to websites or displaying email/contact info which is prohibited by ebay. After reviewing the 3 listings and not finding anything that was against the ebay policy decided to contact live chat.
After a few minutes with live chat it was revealed that ebay's bots now detect links that are direct to ebay such as "see my other items" are classified as links and the bots can't determine which links are different from links that are within ebay to ones that are not.
All fixed now but just a heads up when listing from a sell similar you may encounter the same problem and might have to remove any type of external links on your listing or just go through the hassle of contacting ebay chat/phone call and they will let you disregard the red flagged items.
