"encrypted with 1 passphrase"

[Ángel]

On 2020-07-29 at 10:20 -0700, Ayoub Misherghi via Gnupg-users wrote:
> A gpg says "encrypted with 1 passphrase". Are there situations where a 
> message
> 
> gets encrypted with multiple passphrases?

GnuPG seems to only support encrypting with a single passphrase, but the
OpenPGP format supports multiple passphrases as well (several
Symmetric-Key Encrypted Session Key Packets).