The amount of programming they can do is impressive. While these do not explicitly answer your question about what each ‘E number’ is reporting, @phb is correct in that the numbers are used to quantify billing use totals, export, with ability to report use at flat rates, time of use, seasonal, and other aspects.
The examples on the net generally show understandable words rather than E1, … E12. If yours does not it could be your grid operator (that owns the meter) being ‘helpful’ to someone, but not to their customers?
Apologies I could not be more helpful. Your grid operator might be amenable to defining the ‘E numbers’ for your meter/their grid.
