DC Comics, like many publishers, run an exclusive covers programme for comic stores and other vendors. This enables retailers to order a comic with a cover just for their store, to sell as a collectible or to use for promotion, as long as they order thousands of copies of the issue in question.
Some retailers have run shared exclusive covers, splitting the costs between two or more stores. But this, potentially, could deprive the publisher of an exclusive cover sale.
Last summer, DC Comics representatives made it clear to retailers, that "only one retailer can be listed on the cover. These are not meant to be shared variants." So, while an exclusive cover could be shared from one shop to another, there can only be one retailer name or logo on a cover. Which is how the Fried Pie variants get away with it.
However it seems there is one rule for one and another rule for another.
Such as the release of Justice League vs Suicide Squad #1 on December 21st where four vendors where able to jointly share an exclusive cover with DC, and get their names on the cover….
And retailers who point out to DC Comics, say, that they have been ignored. A change of policy? Favouritism? An error that slipped through? The retailers in question would just like an answer.