Conversation so far:
What did Havelock Ellis write about sterilization?
Havelock Ellis was strongly opposed to the idea of castration for eugenic purposes.
Did Havelock Ellis write a book about sterilization?
In his publication The Sterilization of the Unfit, Havelock Ellis argued that even institutionalization could not guarantee the complete prevention of procreation between the unfit.
How did Havelock Ellis share his views on sterilization?
Were Havelock Ellis's views controversial?
While Francis Galton analogized eugenics to breeding domesticated animals, Havelock Ellis felt that a greater sense of caution was needed before applying the eugenic regulations to populations.

Question: What were the regulations about?
Self-contained rewrite: What were the eugenic regulations Havelock Ellis felt that a greater sense of caution was needed before applying to populations about?