dunno what the current links rule is (they change it fairly often) but at one point they said that a "soft link" was the same as a regular link in regards to their rules. (A soft link being the site name without it being a clickable link. ie: saying yoursite.com is still considered by ebay to be a link even though it's not clickable)
I dont know if they've reworded that or not, but they do pretty much prohibit any mention of a .com in your listing.
I know that doesnt totally answer your question, but i hope it helps some.
Personally, I tend to think they keep some of their rules confusing on purpose so that they can more easily pull a listing. I've even seen some rules in the past where in the text of the rule it said one thing, but the example contradicted it.