Wireshark-users: [Wireshark-users] PCI of a TCP-segment

From: Lisi <lisi.reisz@xxxxxxxxx>
Date: Tue, 11 Oct 2011 17:41:04 +0100
What _is_ "the PCI of a TCP-segment" when referring to Wireshark?  I have 
googled and googled and googled.  I have looked PCI up in an acronym website.  
I am completely stuck.  Can any kind soul enlighten me?

Thanks
Lisi