@bwh The v4 is short for the Version 4 signature format.

@bwh The v4 is short for the Version 4 signature format.

And the story of what is a standard and what is not, is more complicated and debatable, e.g. see https://librepgp.org/index.html#about, especially “The IETF OpenPGP Working Group (WG) at some point decided to give up on its charter to produce an updated specification and instead started to re-invent that standard. Whether this is in line with IETF rules is questionable.”

@letoams Yes, AFAIK LibrePGP’s signature format (v5) it incompatible to v6’s.