FORMAT REFERENCE
The vCard MIME Type
The standard media type for vCard data is text/vcard. File extensions commonly include .vcf and .vcard.
Last reviewed
Why the MIME type matters
A correct content type helps browsers and receiving applications understand that a file contains contact-card text rather than an arbitrary download.
Practical caveat
Some older systems rely mainly on the filename extension. Use a .vcf extension for broad compatibility and keep the card structure valid.