IFR means instrument flight rules. It is just that - a set of rules to which one operates to (primarily) allow one to fly in clouds.
IF is the actual action of flying in cloud (or under the hood etc).
They are two separate things. A VFR flight even above MSA and quadrantal levels cannot be considered the same as an IFR flight. The latter involves radio procedures, navigation tolerances, flight plans.
Should you be flying VFR and choose to change category to IFR (and are properly rated) and abide by the aforementioned rules, then you could note that you flew from that point on under the IFR.
You should never be flying IF under the VFR. Think of the words.. Visual Flight Rules. You are required to see and avoid, and you can't do that in cloud.
I would argue that IFR could be recorded as block to block as you have different radio procedures on taxi under the IFR.