pcap_list_datalinks(3) on FreeBSD
The text 666f006afcbd, as FreeBSD 9.0-RELEASE, FreeBSD 8.4-RELEASE, FreeBSD 8.3-RELEASE, FreeBSD 8.2-RELEASE, FreeBSD 8.1-RELEASE, FreeBSD 8.0-RELEASE shipped it.
get a list of link-layer header types supported by a capture device