MarciK
Welcome! :)
It looks like we have a similar way of organizing our books. Mine are
Reference
General (I have integrated vegetarian into these, although I used to keep them separate)
Meat
Specific ingredient (eggs, yogurt, etc. and specific food types like soups)
Make ahead/Batch/Freezer cooking
Regional
Holiday/Entertaining/Bar
Desserts
Appliance and method cooking (sheet pan, dutch oven, rice cooker, Instant Pot...)
Fermenting and Preserving
Baking & Pasta
Beans & Grains
Vegetables
Herbs
Fruits
I garden so I have a lot of books that focus on vegetables, fruits and putting up.
I have these small 1/4" round green stickers that I put at the base of the spine when a book has been indexed. That way I know which books I will need to manually check if I'm looking for a particular recipe. It also helps me when I am looking for a new book to index.