Under CSV format with only items i) and v) included, the data might consist, for example, of records:
1,2,12.0
1,3,13.0
3,2,32.0
…
Indicating that cell (1,2) has a value 12.0, etc. etc. Alternatively, using spaces and fixed columns, the same data might appear as:
1 2 12.0
1 3 13.0
…
And both data sets could be happily read as “free format”. Note that in this case we are assuming that only sequential row and column numbers are given, not their zone names (i.e., i) above but not ii)).
Alternatively, if the zone names for sequential zones 1,2,3 were 10,20,30, then only names, not sequential numbers, (method ii) could be used, as in:
10,20,12.0
10,30,13.0
30,20,32.0
…
Finally, belt and braces, both sequential and zone names could be used as in:
1,2,10,20,12.0
1,3,10,30,13.0
3,2,30,20,32.0
…
Clearly in this case one would have to be careful that a sequential 1 was always followed by the “name” 10 (whether input as a row or a column).