The nomination of Limbaugh was in 2007 by something called the Landmark Legal Foundation, whose president is Mark Levin. However, it was not considered a valid nomination.
According to the Nobel Prize website,
A nomination for the Nobel Peace Prize may be submitted by any person who meets the nomination criteria. A letter of invitation to submit is not required.
And
There are 338 candidates nominated for the 2025 Nobel Peace Prize, of which 244 are individuals and 94 are organisations.
So while the list of nominees is indeed kept secret, most anybody can submit a nomination and then brag about it, even if it’s not considered valid.
For the record, the criteria for submitting a valid nomination is, again according the above link:
- Members of national assemblies and national governments (cabinet members/ministers) of sovereign states as well as current heads of state
- Members of The International Court of Justice in The Hague and The Permanent Court of Arbitration in The Hague
- Members of l’Institut de Droit International
- Members of the International Board of the Women’s International League for Peace and Freedom
- University professors, professors emeriti and associate professors of history, social sciences, law, philosophy, theology, and religion; university rectors and university directors (or their equivalents); directors of peace research institutes and foreign policy institutes
- Persons who have been awarded the Nobel Peace Prize
- Members of the main board of directors or its equivalent of organizations that have been awarded the Nobel Peace Prize
- Current and former members of the Norwegian Nobel Committee (proposals by current members of the Committee to be submitted no later than at the first meeting of the Committee after 1 February)
- Former advisers to the Norwegian Nobel Committee