The 2018 version of the A2C specification has been published today. This is the version of A2C that will be used for the pilot for vocational qualifications in 2018-19.
This does not affect the A2C Migration Application.
If you are a centre with a commercial MIS system your supplier will be implementing A2C and will notify you when an upgrade is available. Only centres with their own “homegrown” systems need to implement A2C themselves.
The spec can be downloaded from here.