Two or more candidates who have established separate campaign finance entities may form a slate. After establishing a campaign finance entity in accordance with § 13–202(c) of this subtitle, a candidate may join a slate. To join a slate, a candidate shall file a written notice with the State Board. The notice shall specify: the name of the slate that the candidate has joined; and the date on which the candidate joined the slate. A candidate may join a slate or continue as a member of a slate only if: the candidate has filed a certificate of candidacy; or the candidate is an incumbent officeholder; and the deadline for filing a certificate of candidacy for the office the candidate holds has not passed.