If you want to research your question, it’s almost certainly in one of the RFC at ietf.org.
A list of DHCP related RFC in chronological order
Appendix C: DHCP RFCs
I hadn’t thought much of this, but DHCP is fundamentally a broadcact protocol (cannot be UDP or TCP because the client does not yet have an assigned address) so it would make sense that kind of traffic should be configured so it would only be listened to, depending on whether the Host is a DHCP server, Host without an address (but identifiable by MAC address) or ignored because the Host already has an IP address.
TSU