No Aircraft
Communication Breakdown; Confusion
Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Weather / Turbulence
Flight Crew Diverted
Human Factors; Procedure
I was settled into my hotel; having just diverted to ZZZ due to smoke and convective activity. I received the two emails I enclosed with this report. They tersely reported 'Southern California ACA' (Airspace Coordination Area) and 'Northern California ACA' and gave a range of altitudes. I had never heard of an ACA; so I used Google to find the FAA acronym list. There was no mention of an ACA. The email also mentioned 'Notice Number: NOTCXXXX' so I searched this as well. I found a reference to ZZZ1. That notice expired December; 2008. My cellphone was having trouble making phone calls; so I didn't call [company] until the following day. At that point; I was informed that nobody (including the FSS briefers) previously knew what an ACA was. The briefer pointed me to an FDC NOTAM that gave further information. There was no reference to the FDC NOTAM in the emails I received. I would not have been able to find the FDC NOTAM myself until the FSS briefer pointed me toward it. I would have hoped that the FAA had learned its lesson after declaring ATC Zero events earlier this year and failing to inform pilots what this meant. If the FAA is going to use terms and acronyms; these need to be defined in advance; and educational materials need to be disseminated to pilots and FSS briefers. Also; if FAASafety.gov is going to send emails to pilots; these emails should have useful information.
Pilot reported diverting due to weather; then received email notifications from FAA that were confusing.