Yes, you can definitely use a card index for note-taking. In fact, many people find card indexes to be a useful and convenient tool for organizing and storing notes. Here are some tips for using a card index for note-taking:Choose a system: Decide on a system for organizing your cards. You could organize them alphabetically, by topic, by date, or by any other method that works for you.Choose the size of cards: Choose the size of cards that works best for your needs. Common sizes include 3" x 5", 4" x 6", and 5" x 8".Use one card per idea: Write one idea or piece of information on each card. This will help keep your notes organized and easy to reference.Include keywords: Include keywords on each card to make it easier to find relevant information later.Use dividers: Use dividers to separate different topics or sections in your card index. This will help keep your notes organized and easy to navigate.Carry it with you: A card index is a portable tool, so you can take it with you wherever you go. This makes it easy to take notes on the go and to refer to your notes when you need them.Overall, a card index can be a useful and efficient tool for note-taking, especially if you prefer a physical, tangible way of organizing and storing information.