If you are using GNSS Solutions in the United States to process observations, then this information may be of great value to you:
This link [ GNSS_Solutions_NAD83_G12A ] will get you a copy of the latest version of step-by-step white paper on maximizing reference frame accuracy when using GNSS Solutions with NAD83_2011 and GEOID 2012A.
The paper also shows how to
o update all of the Antenna Calibrations with Absolute values in one step
o import all of the NGS CORS sites in one step
o add GEOID12A to the available vertical datum
Plus as a bonus: the top 10 GNSS Solutions Screw-Ups (from my perspective)
Happy New Year!