I did a brief search for "packed decimal field". I found a message talking about the Convert::IBM390 module that handles translating between ASCII and EBCDIC and packed decimal fields.

If the packed decimal fields in random places, you may have a hard time pulling them out. In your example, it is obvious that "`pr%` isn't like the rest. But I don't know how a parser would recognize the field. But there are no separators between fields.