FreeBSD password databases (/etc/pwd.db, /etc/spwd.db) can contain
records in one or both of two versions:
* v3, a legacy architecture-dependent format
* v4, the current architecture- and endian-independent format
When v4 support was added in 2003 (r113596) pwd_mkdb emitted both v3 and
v4 record
> FreeBSD password databases (/etc/pwd.db, /etc/spwd.db) can contain
> records in one or both of two versions:
> * v3, a legacy architecture-dependent format
> * v4, the current architecture- and endian-independent format
>
> When v4 support was added in 2003 (r113596) pwd_mkdb emitted both v3 a
