Eps are usually just enhanced singles, and typically as part of an album release a few singles or eps are released containing lead tracks from the album. And often it is unclear whether a 4 track release is an Ep or a single, even if there is no mention of EP on the cover its often considered an EP by some.

As a user I would like to see Singles and EP's displayed together, then I can see chronological list of official non-album releases, this is how Discogs does it.