Thanks Satish,
I think I understood something.
Easy to follow documentation and SAP are contradictory terms :-). One is antithesis of another. Oxymoron.
Several years ago when a world class academy consultant with 15 implementation years experience taught me DP for 750 USD a day for 2 days in a 5 star setting,, I do not recall he using the word "technical period" even once in the entire 2 day course. The thick 2005 guide that I now pulled out from my garage does not mention the world technical period anywhere. I presume there were no technical periods in DP then :-)
Thanks. Appreciate your patient answers.
BS.