BCC - Blind Carbon Copy

Hello pchdwck,

Welcome to the Apple Support Communities. We understand you want to send messages without the other recipient's knowing in a group message and will explain.

This wouldn't be possible in Messages, only in the Mail. You can leave any feedback here: Product Feedback - Apple

Thanks.

In Mail app, start new message, then tap on "CC/BCC, From:" field to expand it, and enter email address under BCC filed.