Located under 'Player>Books>Compendium of Love', this book allows you to track how you can breed specific species in the Breeding Shop.
As of September 2022, all combinations can be viewed. However, you must still perform the combinations to complete an entry.
You will receive a confirmation message in the breeding dialogue when you have successfully accomplished a new combination.
Complete as many entries as possible and you might just unlock a particularly sexy Soul Puppet.
While completing the compendium of love and choosing different species, you will receive this guidance.
This information can be viewed from a creatures' status screen under the "Breeding" Tab, Species Status screen under the "Egg Info" Tab, and when selecting breeding partners in Freya's Shop.
Breeding hints were written in a colaboration with the following players: