Hi Angliholic, Taking your second question first, yes, your understanding is correct. "Confidential" can be replaced by "private" in this case, but "confidential" is the best word. Confidential information should be proteced from public disclosure, and revealed only to people who have a need for it - like teachers, the school nurse, etc.
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.