archive_write_blocksize(3) on FreeBSD
The text 97d27e5c6d61, as FreeBSD 12.1-RELEASE, FreeBSD 12.0-RELEASE, FreeBSD 11.3-RELEASE, FreeBSD 11.2-RELEASE, FreeBSD 11.1-RELEASE, FreeBSD 11.0-RELEASE, FreeBSD 10.4-RELEASE, FreeBSD 10.3-RELEASE, FreeBSD 10.2-RELEASE, FreeBSD 10.1-RELEASE, FreeBSD 10.0-RELEASE shipped it.
functions for creating archives