"Orange arrow" or "Golden arrow" is a linked button in SAP Business One. I prefer calling it "Orange arrow" because the color of the arrow is orange. It is not golden.
However, it will be called "Link Arrow" in the book to prevent any confusion.
Link arrow is an excellent tool to get detailed information directly from the query result. This is one of the best functions within SAP Business One that makes SQL query a much more powerful tool than some other printable only reporting tools. When you click on the link arrow, you will immediately open the linked document. It is very convenient.
Some queries will hide link arrows by default. Here is a partial list: