[tequila]

Am I missing the section where it says these stack with other worn armor? The text for Armor (p265, bottom left) clearly states that "multiple items to not stack unless noted."  Nothing under Helmets or Shields (p266, bottom right) states that they stack.  It makes sense that they would stack with other worn armor since they have done so in at least the last two editions. 

[Hephaestus]

That might need some clarification in the blurb for helmets. I can't find anything there that would note them as stack-able. Same with ballistic and riot shields.

[sigfriedmcwild]

The closest you'll get is this section on p108

Defense Boost
This quality is on Armor and bumps up the Defense Rating of a character. Most Defense Boosts from pieces of armor are not cumulative, though qualities, augmentations, and supplemental armor like helmets, shields, and pads can provide a little bump here and there.

[markelphoenix]

Yeah, they dropped the ball on what does and doesn't stack in the CRB.

[tequila]

The closest you'll get is this section on p108

Defense Boost
This quality is on Armor and bumps up the Defense Rating of a character. Most Defense Boosts from pieces of armor are not cumulative, though qualities, augmentations, and supplemental armor like helmets, shields, and pads can provide a little bump here and there.

Funny, I read  that section early this morning when someone asked about what Defense Boost and Armor Rating were. Totally missed that.    I think that is good, but there should still be something with helmets and shields as well.

[Xenon]

• Dermal Deposits - Quality
• Armor - Spell
• Mystic Armor - Adept Power
• Bone Lacing - Cyberware
• Dermal Plating - Cyberware
• Cyberlimb Armor - Cyberware
• Orthoskin - Bioware
• Helmets - Supplemental Armor
• Shields - Supplemental Armor
• Pads - Supplemental Armor