Samuel,

IMHO it is all quite logical and 'simple'. Let me explain.

If you want to make use of setting rules based on committed data you need first to determine when you consider the row being committed. By default this is when the row has been saved. But you can alter this decision by augmenting IsCommitted for example when you have rights to change an already stored row in the table. The row being committed does not do much with the row itself but is being used to find out if you are allowed to switch parent rows. So then to column level. You can tell the DD to block data entry when the column (field) carries the DD_COMMIT attribute and the row is commited. The IsFieldCommitted simply only looks at the DD_COMMIT option but you can write alternate code to overrule this. For me mainly based on rights. So once saved you cannot change the amount of articles ordered unless you are a manager.