兹【zī】

兹 is the first word of an official document: a notice, a certificate, a letter of introduction or appointment. It means "now, at this point" and marks the sentence as the formal act the document performs. A verb follows it at once.

The usual openings

兹定于 announces a date. 兹证明 opens a certificate. 兹有 introduces a person the document is about, typically someone being sent somewhere, and the rest of the sentence says why.

兹因 gives the reason for the notice, and 兹聘请 opens a letter of appointment.

Start, not end

兹 opens the document and 特此 closes it, so many notices carry both. 兹 never goes in speech or ordinary prose.

• × 我兹告诉你明天开会。 → 我告诉你明天开会。
• × 会议定于周五召开，兹。 → 兹定于周五召开会议。