Using "In-Reply-To" instead of "Subject"

Can “Request Tracker” use the “In-Reply-To” header to figure out into which ticket a message should go into or if it should create a new one?

I’m reading its documentation and I only see references to parsing the “Subject” line. I’ve seen a few posts more than 15 years old on the forum discussing it, some even with patches, but it’s not clear to me the current state of things.

I am aware of the issue that people often create new tickets by replying to an old ticket. I don’t mind that. My goal is to create a sort of “invisible” ticket system, where those that sending the emails do not get automatic replies, do not have the subject line modified, and are not exposed to a ticket number.