vCard (.vcf) files are the most durable files for contact information, in my experience. I even have some from my old Palm, and they are the default export format for contacts in Android.
It’s a plain text format, just like markdown.
I’d love to use Obsidian to edit vcf files like it handles editing properties.
BEGIN:VCARD
VERSION:2.1
N:Watson;John
FN:John Watson
EMAIL;INTERNET:[email protected]
TEL;CELL:555 1312222114
UID:"John Watson, [email protected]"
NOTE:He works with [[Sherlock Holmes.vcf]].
END:VCARD
If I had each contact in a separate vcf file, I could use the NOTE
attribute to link the files and visualize the relationship structures in the graph view.