非公開

1. Origins, structure, and basic meaning

• Structure: 非公開 is read as ひこうかい and is a noun-like expression in which 非 negates 公開, indicating that something is not open to the public.
• Basic usage: It is used for holding a meeting privately or restricting public access to material under investigation.

2. Common pitfalls and similar expressions

• Manner with で
  • In 非公開で行う, で describes the private manner in which the meeting is held.
• Predicative state
  • 一般には非公開です states that the material is unavailable to the general public, not that it does not exist.