Extraction card: this is the most used card, mainly to extract the required original data. When copying, the purpose should be clear, the extract should be accurate and the source should be accurate. Sources include author, title, edition, chapter and page number. Check immediately after picking, so that there is no shortage of time. The extracted cards can be divided into large categories, then into medium categories, and finally into small categories, which are bound into volumes and listed in advance for easy reference.

Summary card: after reading a book or an article, write the main contents on the card in your own words, which is conducive to timely reference. When writing a summary card, you should refer to the preface and postscript, so that you can have a general understanding of the ins and outs of this book, so that the summary written will be more accurate and refined.

Index card: Some monographs or papers are very important, so information is everywhere. It's really hard to remember and answer. This requires writing down the title, issue number, chapter, page number and content of the article in monographs or newspapers and periodicals, and placing them in categories for future reference.

Back card: write down the useful materials you usually hear in a small notebook, then transfer them to the card, sort them out at any time, and keep them in categories.

Experience card: record your usual thoughts, experiences or feelings. Take a few cards with you, and the occasional thoughts or ideas will be recorded immediately.