Originally Posted by hslightnin

In order to maintain required operational control and ensure the highest level
of safe and reliable operations, the SOC must be able to provide the Pilot-in-
Command and other personnel who perform operational functions with
access to the necessary information for the flight. To accomplish this, the
SOC will use several methods to positively contact crews, including but not
limited to dispatch release notes and SELCAL. This positive notification must
be complied with per instructions as detailed in these messages. Please refer
to GOM Chapter 3, page 3.4, Section 3, Paragraph C, and Chapter 4, page
4.28, Section 35 for guidance on this subject.
The Captains signature on the dispatch release indicates that you are
responsible for the release and its entirety. If a message is sent for First
Officer or Flight Attendants, you will be held accountable for providing the
information to those crewmembers. Vigilance with regards to SELCAL
monitoring is mandatory, as this is the only method of maintaining operational
control over our aircraft in the enroute environment.

Mesa had this memo a few weeks ago now its out on Freedom too