This might be the one article that stayed the longest in my to-read list: Since January 2021! Here Tom MacWright goes into a bit of detail about GEDCOM, an industry-standard for genealogical data dating back to 1984. It’s the data format that pretty much every family-tree software out there supports at least when it comes to importing/exporting. He also explains some of the issues with the standard especially around the handling of sex (no intersex value, which has been resolved since then) and relationships (always a
Luckily, one aspect of the article is outdated by now: GEDCOM has seen some active development since the article was published with FamilySearch pushing out version 7 and now once again actively maintaining it.