You may want to communicate with your buyer while in a Quote. Here are the steps to do so:
Navigate to the left menu button > Customers > Quotes > Click on a specific product > Click Product Details
Once in the product details you can click on any product field detail and leave a sticky note. You may notice a toggle once the pop-up box appears on the right-hand side. This provides the option to leave the sticky note for either your buyer or just your internal colleagues.