How to hide the caret in RichTextBox?

Well this proposed solution is worthy of a sneaky Halloween trick, but ... it works ... kinda ... :)

1. put a real small label on your Form, set its Text to an empty string. set its background color to match the Form color, or you can even set its background color to Transparent. Or put it behind something :)

2. Define 'Enter and 'Leave events for your RichtTextBox1:

private void richTextBox1_Enter(object sender, EventArgs e)
{
    // want to clear any current selection: use this:
    //richTextBox1.SelectionLength = 0;
    //richTextBox1.SelectionStart = 0;

    // what's unfortunate here is that
    // there is no simple way to turn-off
    // the cursor completely ... not without
    // ... as I understand it ... using pInvoke
    // whether any of the alternate cursors you
    // can change it to would be satisfactory
    // to you ... I don't have a clue !
    // Want a circle with a diagonal stripe:
    // richTextBox1.Cursor = Cursors.No;

    label1.Focus();
}

private void richTextBox1_Leave(object sender, EventArgs e)
{
    Cursor = Cursors.Default;
}