noun which may take the genitive case particle 'no'
Describes something not officially recognized or approved, such as a record, event, or organization.
That record is unofficial, so it is not officially recognized.
非公認のイベントに参加するのは自己責任だ。
Participating in an unauthorized event is at your own risk.
非公式 also means 'unofficial' but is more common and broader; 非公認 emphasizes lack of official recognition or approval.
Compound of 非 (hi, 'non-') and 公認 (kōnin, 'official recognition').