QUOTE (suoq @ Sep 22 2011, 03:36 AM)

Arsenal pg 50-51
FFBA and PPP can be assumed to change the specific body contours.
An assumption. I could reasonably assume that the reason they don't typically count as another armor worn is because they don't change much.
QUOTE
So, unlike the implication above, they're don't work with "helmets", they work with a specific helmet.
Intended to be worn with a specific helmet. But it doesn't specifically say it can't work with any other helmet. This also says nothing at all about shields, unless you want to argue that for some reason your military grade armor can't work with a regular old riot shield and you MUST use a military shield to get the advantage.
QUOTE (SecureTech AR 49)
These armor pieces do not count as separate armor for purposes of encumbrance; instead, these items modify the rating of armor worn by their rating just as helmets and shields do (see Helmets and Shields, p. 317, SR4, and Armor and Encumbrance, p. 149, SR4).
SecureTech obviously does NOT count as armor worn, and thus can be worn with military armor no problem.
QUOTE (Form Fitting Body Armor AR48)
When worn in combination with other pieces of armor, the form-fit armor rating is added to the other armor’s rating (ignore the rule that only the highest value applies in the case of form-fitting armor). When determining encumbrance, however, add only half the rating (round down) of form-fitting body armor to the ratings of other armor when comparing them to the wearer’s Body x 2 (see Armor and Encumbrance, p. 149, SR4).
Like I mentioned before this one is more sketchy, and I could see it go either way. On the one hand, this one doesn't have the explicit statement that "this does not count as armor worn", and instead has "ignore the normal rule that different armors don't stack" but it seems to me the main reason it doesn't is because it needs to go on and explain how its encumbrance is handled differently.
Also, given the form fitting suit is already tailored to you, and your main issue is the military armor is also tailored to you, why couldn't you have the military armor tailored to you while you are wearing the form fitting armor?