Body Slots

Every character has the following 27 slots (provisionally). Gifts that can’t be fit into a slot may be left at the Vats until switched out.

Head: Scalp, Eyes, Ears, Mouth, Jaw, Face, Neck, Brain.
Torso: Shoulders, Lungs, Heart, Pecs, Back (upper), Spine (lower), Stomach, Abdomen.
Limbs: Arm (2), Hand (2), Leg (2), Hips, Shins (2), Feet (2).

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Everybody has their standard gift pool (3 career, 3 cast, Personality, Combat Save, Local Knowledge, Language) plus Literacy, Anima Banner, one extra Increased [Trait], and 6 free gifts.
Aside from those 6, none of those require body slots.
Eidolon, Perfected Lotus Matrix, and Increased [Trait] never require a slot.
Knack for [Skill], however, ALWAYS does. Alchemicals are not necessarily skilled in every area, but they can install programs to make them hypercompetant.
Favored Use does not (obviously, as it is not a gift) but the Extra Favored Use gift requires a slot.
For a complete list, see this page

Body Slots

War and Pieces Act 2 DoctorLibrarian