25 Pa. Stat. § 2867
The names of candidates for nomination as President of the United States, and the names of all other candidates for party nominations, and for election as delegates, alternate delegates, members of committees and other party officers, shall be printed upon the official primary ballots or ballot labels of a designated party, upon the filing of separate nomination petitions in their behalf, in form prescribed by the Secretary of the Commonwealth, signed by duly registered and enrolled members of such party who are qualified electors of the State, or of the political district, as the case may be, within which the nomination is to be made or election is to be held. Nomination petitions of delegates and alternate delegates to National conventions committed to support a particular presidential candidate must be signed by the particular presidential candidate to whom support is pledged before it can be certified by the Secretary of the Commonwealth. The name of no candidate shall be placed upon the official ballots or ballot labels of a political party to be used at any primary, unless such petition shall have been filed in his behalf. In no event shall any person's name be printed upon the official ballots or ballot labels of any party for the office of delegate, alternate delegate, member of committee or other party officer, unless he is a duly registered and enrolled member of said party.
25 P.S. § 2867