[daip] Cookbook suggestion

[Walter Brisken]

I noticed a minor point that I think could use some attention in the AIPS 
cookbook:

In the 31-Dec-2004 cookbook, section 9, page 42, it is mentioned that "... 
for polarization experiments, the parallactic [spelled wrong in the book] 
angle correction (VLBAPANG), ..."

Note that for phase-referencing (especially astrometry) the parallactic 
angle correction is essential as the parallactic angle difference between 
calibrator and target is different at different stations, and thus there 
is an extra phase error that needs correcting.

Also under section 6 of page three, this correction is suggested, but 
probably not strongly enough.  Perhaps again in section 9.4.4.3 it should 
be mentioned.

-Walter