> Oh, yes - which is why I emphasized "is". But ASCII text is easy to test for, which lets you fast-track into exception handling - "Tell Sales that Customer data is not as represented", "Trouble-shoot internal data source", etc.

Oh with that I mean the ASCII control characters appearing in inputs. So some columns would have record end markers in for example.

If I'm able to make everyone dealing with the reading and writing add specific characters to be used for start/end/etc I'd rather just tell them to swap to a parquet reader unless they've got a really good reason.