Promissory Estoppel, Fixed Prices and preparing contracts

I am always looking for interesting things in the CPSM notes and I thought Promissory Estoppel was pretty impressive. The concept follows from British contracting law and generally speaks to one of the many points to consider when preparing contracts. This section has 29 pages with 8 types of "Fixed Prices". Most of these are definitional but quite a lot of material to cover.Coming back to promissory estoppel the key message is that an implied agreement can also result in conflict and disagreement. It is therefore important to spell everything out in writing so that things are clear going forward to contract implementation. The suggestion to follow verbal orders with written documents brought back some of the classic practical learnings I had in my early days after my MBA which basically taught me the same thing  in the real world...