Mopar Performance Purple Mechanical Camshaft - P4120653AE Cam Card

I have read your reply several times and it is pretty clear except the part of the 60* "ICA"
The only ICA term I am familiar with is - Installed Cam Angle - the installed relationship between the cam and crank i.e. advanced or retarded.
60* ICA I dont yet grasp a further explanation please.
ICA = intake closed angle