After an exhausting session with Victoria's Secret Police, Frank May
confessed:

VIFF = Vectoring In Forward Flight. I've read that Sea Harriers in The
Falklands used VIFFing in combat with Argentine Mirages/Daggers.
Especially effective when one was on a Harrier's tail.

Respectfully, "Sharkey" Ward's book failed to mention VIFFing, and he
was very happy to detail Sea Harrier success versus Alconbury's
527th Agressors; plus none of the contemporaneous tactical discussions
from the mentioned it.

[At the time I was posted on Phantoms in Germany and never saw the RAF
Harriers from Gutersloh use VIFFing. But I saw the Harriers quite
often. I never saw any "eye watering" turn rates or radii when I
briefly had trapped one at my 12 o'clock. However I was impressed when
I first saw F-16s square the corner.]

And...this is probably the contentious point, I was under the
impression that USMC pilots were the originators of VIFFing. I can't
recall the source, but believe it came from a poster on this forum.

Juvat