From Steve McIntyre: Left- Briffa reconstruction from Oct 5, 1999 Climategate email. Matches Briffa et al 2001 Plate 3 version up to 1960. Post-1960 values deleted in 2001 version shown in red; right – emulation of IPCC AR3 figure without trick. Briffa shown here in purple for emphasis.
Dr. Richard Muller calls out the “hide the decline” aka “Mike’s Nature Trick” on this YouTube video of a presentation he gave.
For some strong background, see Steve McIntyre’s Heartland 2010 presentation here (PDF)