values, as those are not platform-dependent and appear in the per-file
header of capture files.
Note that the "10MB" in DLT_EN10MB, and the "IEEE802" in "DLT_IEEE802",
are historical (so people don't think DLT_EN10MB is only for 10MB
Ethernet).
Don't describe the DLT_PFLOG header - it's in the format of a "struct
pfloghdr" on the OS on which the file was saved, which is OS-dependent
and release-dependent.
Refer to the pcap-linktype man page in the pcap-savefile man page.