On February 29, the Nebraska Secretary of State said he will place these names on presidential primary ballots:

Republican: Newt Gingrich, Ron Paul, Mitt Romney, Rick Santorum.
Democratic: President Obama.
Libertarian: Roger Gary, R. J. Harris, Gary Johnson, Carl Person, Bill Still, R. Lee Wrights.

Anyone who doesn’t wish to be listed may remove his name no later than March 10. Nebraska is one of the states in which state election officials place presidential candidates on the presidential primary ballot if the candidates are mentioned in news media. Candidates need not bother to apply.