Images of the sources with large position differences between coordinates derived from 8.4/2.3 GHz data with respect to coordinates derived from 23.6 GHz data. Left: J0318 + 1628, also known as CTA21 (position difference –5.10 mas in R.A.). Center: J1217 + 5835—the position estimate at 2.2/8.4 GHz is shown with a green cross and the position estimate at 23.6 GHz is shown with a red star. Right: J1927 + 7358—the offset of the position from 2.2/8.4 GHz data relative to the position estimate at 23.6 GHz is shown with a blue arrow. The images are taken from the Astrogeo VLBI FITS image database, available at http://astrogeo.smce.nasa.gov/vlbi_images.