Stewart-Haas Racing has applied for the trademark for the (4) Standard Character Mark or the #4. Supposedly to be used by Kevin Harvick when he moves over to Stewart-Hass Racing in 2014.
You can see the trademark application / info at uspto.gov (do a search under Stewart-Haas).
Other rumored numbers for Harvick at Stewart-Hass Racing: take the #29 with him from Richard Childress Racing with RCR using the #3 for Austin Dillon. Have heard some rumors the #8 could be in play.
