This is a very useful site for understanding daffodil classifications but may be too tempting: https://qualitydaffodils.com/
If this was a really serious show, we'd have a category for all 12 official classifications of daffodil. But we aren't, so we just differentiate between 4-5 and then have a catch-all category for any of the others. On the day, if you're not sure which yours fit into, just ask us.
Here is a brief description:
Where the central cup (corona) is as long or longer than a the outer petals (perianth). Can be single colour or bi-coloured.
Where the central cup (corona) is less than a third the length of the outer petals (perianth). These coronas can look just like a small central frill.
Where the central cup (corona) is more than a third as long and no longer than the outer petals (perianth).
This relates to the formation of the multiple layers of petals, and they can either be single blooms or multi-headed.
You can put a wide range of daffodils into this category such as split coronas, triandrus, cyclamineus, tazetta etc. Anything multi-headed that isn’t a double would fit in here for instance