Canon Mk2500 User Manual page 29

If you attempt to open an existing file with the old format (.mtd / .md2), a
message may appear to indicate that it has been replaced with a file with the new
format (.md3).
[OK]:
3
When you select a CSV file, the Read Format Selection dialog box appears.
For details about individual setting items, refer to
If you select [1 Line] in [Lines], the first line of data in the CSV file is loaded, but
the second line and the third line are ignored.
The third line of data can be loaded only when [Character Size] is set to [1.3mm
Norm].
The file with the new format (.md3) substitutes for the existing file
with the old format (.mtd / .md2) and then opens.
23
Operating Mk2500PC
"4.5 Format Settings"(P.32).