METAREA definition--clarification needed

I need clarification on the METAREA variable.For the ACS 2009-2011 3 year sample the METAREA variable is based on the 2000 MSA definition, correct?Is this the case for the 1990 and 2000 (decennial census) samples, too?

Thanks!

METAREA uses the same definitions for the 2009-2011 3-year ACS sample as were used in the 2000 Decennial Census samples. These delineations were released by the Office of Management and Budget (OMB) in 1999. The 1990 Decennial Census samples used the 1990 OMB delineations. See the County Composition of Metropolitan Areas and Incompletely Identified Metropolitan Areas for more information on the complexities of the METAREA variable across the time frame you are interested in.

I hope this helps.