Odds are VERY good that you don't care about HDMI 1.2 or 1.2a. It does support DSD(Super Audio CD) bitstream, but as of today this is not very useful even if you have an SACD player with HDMI because of the lack of receivers/processors which decode DSD.
The following is a quote from hdmi.org about 1.2a which adds more rigorous controls:
Consumer Electronic Control (CEC) features and command sets and CEC compliance tests are now fully specified.
Creation of version 1.2a of the HDMI Compliance Test Specification (CTS), which includes a CEC Supplement. HDMI CTS 1.2a has been updated for technical consistency with HDMI Specification 1.2a as well as to the recently released HDMI Specification 1.2. o Significantly, CTS 1.2a contains additional cable and connector testing and Authorized Testing Center (ATC) submission requirements. Specifically, under CTS 1.2a, the Adopter shall submit for testing to the ATC any new HDMI cable whose length exceeds previously tested cables.
Additionally, HDMI Licensing, LLC will maintain a list of approved connectors. For a device to pass CTS 1.2a testing at an ATC, all connectors on such device must appear on the approved connector list. To add a connector to this list, the vendor must submit to the ATC or HDMI Licensing, LLC full and passing testing results.