First I want to thank 'Hemdian' for making all the errata files avail for d/l.

Afterwards, while skimming some of the files, I came across this gem;

Trade between planets depends on demand for goods at each end of the trading route. Because of the expense of interstellar transportation, most worlds strive to be self-supporting;

they produce their own building materials, food, and necessities.

However, there are still wide varieties of trade goods that can and must be carried between the stars.

The trade and commerce flowcharts present the procedure for locating goods to be shipped and locating markets. "

Seems Don was a Traveller after my own heart!

Wish I had had the opportunity to meet him.