This dialog box allows you to configure what the edit mode cursor looks like. Changing the edit cursor can be useful on certain screens so that the cursor stands out more against the text and color scheme you choose.
"CRiSP is awesome, especially for anyone who likes to use Brief on the PC, and hates vi. I use it for all my code development and maintenance tasks. It's also great for editing binary files or very large files, or files which have very long lines, which cause other editors to choke."