We could use the HL7 pipe ‘|’ and all enjoy that hell.
For those unfamiliar with the atrocity that is HL7v2, the format is essentially CSV, but with the record separator set to a lone CR, and the field separator usually set to |. Usually, because the format lets the consumer of the format redefine it, for whatever reasons. (The first use of the field separator it determines whatever character it will be. Thankfully, the first use is in a fixed spot, so it's determinable, but still. Oh, but we don't know the character encoding until like the 18th field in … and it doesn't necessarily have to be an ASCII superset. So I have no idea what an HL7v2 message in a non-ASCII superset even looks like, or how a parser is even supposed to reasonably parse such a thing. I presume attempt a decoding in all possible decodings, and then see which one matches the embedded character set, and pray nobody can create a polyglot?)
There's also further separators, delimiting within a field.
It also has its own escape sequences, to deal with the above.
… and it is what carries an unfortunate amount of medical data, and is generally how providers interoperate, despite the existence of more civilized standards like FHIR
Did I mention that subcomponents (if you look at it like a CSV, cells are further subdivided into components & subcomponents, so subcomponents are sort of where we hit "cell text", if you want to keep going with that broken analogy) — contain escape sequences, so that you can have things like the field separator. Normal stuff, so far. The escape sequences also include highlighting, binary blobs, and a subset of roff.
Since it was the only column like that, the # of columns to the left of the annoying column and the # on the right would always stay the same. So it was pretty easy to clean.
Hell indeed.
Seriously rough.
