I recently generated the parent-child and ancestor-progeny data for the ICD-10 diagnostic codes. You can find them on the GitHub repo I set up.

While generating the codes was a pretty straightforward matter of =vlookup() and =left(), I discovered only after exporting from Excel 2010 to a tab-separated text format that Excel or Word had converted my ASCII dash (-) and ellipses (…) into special dash (–) and ellipses (…) characters somewhere along the way.

I was using Notepad++ to review the file generated and I decided to determine just what characters existed in the CDC-provided data. I built up the following PCRE regex one piece at a time until I had the exact list (case insensitive):

[^-0-9A-Z trn.,[]/()'%<>=+%]

Of course, upon reflection, I just realized that J has a great way to find the characters:

Right after the command is the result, which starts with a…