Will,
IPsec is spelled "IPsec". Not "IPSEC".
grepping through the messages in my ipsec WG folder, I find:
IPSEC 113 times
IPsec 104 times
IPSec 38 times
I also see that the IETF Working Group description begins:
Rapid advances in communication technology have
accentuated the need for security in the Internet.
The IP Security Protocol Working Group (IPSEC)
will develop mechanisms to protect client
protocols of IP. A security protocol in the
network layer will be developed to provide
cryptographic security services that will flexibly
support combinations of authentication, integrity,
access control, and confidentiality.
Ian.