Whats the right name for fixed position files?

Question

You can structure data in various ways: for example comma separated or tab separated.

But you can also structure data on positions. So, for example, the first 20 characters are meant for a phone number, the following 2 characters are meant for the age of someone etc...

How would you call such a file in general?

Answer 1

If you had id[3]name[5]phone[6]

001Liz  882833
002Paul 892733
003John 927477

this is a fixed format file.