StarFIST (slightly OT)

I started reading a book by Sherman and Cragg called "STARFIST: First To
Fight" (book 1), on the hopes it might make for a good SGII
idea-generator,
and have come across an acronym I can't quite decipher, and so far have
not
seen an explanation for it's meaning (I who live in a WORLD of
acronyms!).

Anyone else read this book or this series (assuming the other books are
out/have been published)? If so...what does 'FIST' stand for? As in
"...was
then assigned to duty with the 34th FIST on Thorsfinni's World...." Is
it
a common one I'm just 'spacing'? I thought 'Fast Infantry Strike Team',
but
in my mind 'team' isn't an entire battalion or anything.

Mk
------------------------------------------------------------------------
---
If the conquest of a great peak brings moments of exultation and bliss,
which in the monotonous, materialistic existence of modern times nothing
else can approach, it also presents great dangers.  It is not the goal
of
*grand alpinisme* to face peril, but it is one of the tests one must 
undergo to deserve the joy of rising for an instant above the state of 
crawling grubs.
				       -Lionel Terray, 1965