Import Data Matrix

Hi everybody, I need clarifications about data matrix import.
I will refer to this example posted by Richard Ay two years ago in this post.
Every row, i.e. every element, in the file is made of 13 values, but the Caesar technical reference manual lists only 12 values to make an element.
I don't understand what the 13th column in the file is for.

Second problem, I don't understand how to write the ELMT column since I can't find a rationale for this column in the example file.

Third and last, what does the 12E13.6 format mean?

Thanks a lot

The items in this neutral file are all described in the User's Guide (the section on interfacing).

That 1st column is a simple counter, more for you information than anything else. The software doesn't use this value.

The 13th column is an extension we were working on - ignore this.

The 12E13.6 format defines how the data is expected in the file:
a) there are 12 fields
b) the format can be exponential
c) the fields are 13 columns wide
d) the fields can have 6 digits of precision (although this value is overridden by the actual data)

Wonderful!
Where does this format definition (12E13.6) come from? I searched the web but found nothing.

Other, more current references may be available but Google "FORTRAN read format".