About time. For those unaware, RRP and EPP are the main protocols for registrars to talk to registries changing domain, contact and host details. EPP is replacing RRP. With the enforcement of EPP in .com, the main barrier to entry for new registrars has come down and pretty much all the main TLDs and most of the new ones too now all use EPP. One system to rule them all…

Registrars who support .com domain names will use the Extensible Provisioning Protocol (EPP) system by October 28. …There will be an additional step when trying to transfer a .com domain name among registrars. Specifically, a piece of information called an EPP code (aka auth code, EPP key, transfer secret) must be obtained from the current registrar and submitted to the gaining one prior to approving with the latter.

Source: Additional .COM Domain Name Transfer Requirement by October 28