Didn't matter for me but I remember GoKiller commenting on the fact that you should put your items before the last item for that list for that faction (which works for me). For example:
["british_iniskilling_helmet_trumpeter", "Dragoon Helmet", [("british_iniskilling_helmet_trumpeter",0)], itp_merchandise| itp_type_head_armor |itp_civilian|itp_doesnt_cover_hair|itp_attach_armature ,0, 4 , weight(0.5)|abundance(100)|head_armor(15)|body_armor(0)|leg_armor(0)|difficulty(0) ,imodbits_cloth ],
["british_lifeguard_helmet_ranker", "Horse Guard Helmet", [("british_lifeguard_helmet_ranker",0)], itp_merchandise| itp_type_head_armor |itp_civilian|itp_doesnt_cover_hair ,0, 4 , weight(0.5)|abundance(100)|head_armor(8)|body_armor(0)|leg_armor(0)|difficulty(0) ,imodbits_cloth ],
["british_lifeguard_helmet_officer", "Horse Guard Helmet", [("british_lifeguard_helmet_officer",0)], itp_merchandise| itp_type_head_armor |itp_civilian|itp_doesnt_cover_hair ,0, 4 , weight(0.5)|abundance(100)|head_armor(8)|body_armor(0)|leg_armor(0)|difficulty(0) ,imodbits_cloth ],
["british_lifeguard_helmet_trumpeter", "Horse Guard Helmet", [("british_lifeguard_helmet_trumpeter",0)], itp_merchandise| itp_type_head_armor |itp_civilian|itp_doesnt_cover_hair ,0, 4 , weight(0.5)|abundance(100)|head_armor(8)|body_armor(0)|leg_armor(0)|difficulty(0) ,imodbits_cloth ],
["japanese_levy_ranker_hat", "Japanese Levy Ranker Hat", [("japanese_levy_ranker_hat",0)], itp_merchandise| itp_type_head_armor |itp_civilian|itp_doesnt_cover_hair ,0, 4 , weight(0.5)|abundance(100)|head_armor(8)|body_armor(0)|leg_armor(0)|difficulty(0) ,imodbits_cloth ],
["japanese_levy_officer_hat", "Japanese Levy Officer Hat", [("japanese_levy_officer_hat",0)], itp_merchandise| itp_type_head_armor |itp_civilian|itp_doesnt_cover_hair ,0, 4 , weight(0.5)|abundance(100)|head_armor(8)|body_armor(0)|leg_armor(0)|difficulty(0) ,imodbits_cloth ],
["japanese_levy_nco_hat", "Japanese Levy Nco Hat", [("japanese_levy_nco_hat",0)], itp_merchandise| itp_type_head_armor |itp_civilian|itp_doesnt_cover_hair ,0, 4 , weight(0.5)|abundance(100)|head_armor(8)|body_armor(0)|leg_armor(0)|difficulty(0) ,imodbits_cloth ],
["japanese_imperial_officer_hat", "Japanese Imperial Officer Hat", [("jap_imperial_officer_hat",0)], itp_merchandise| itp_type_head_armor |itp_civilian|itp_doesnt_cover_hair ,0, 4 , weight(0.5)|abundance(100)|head_armor(8)|body_armor(0)|leg_armor(0)|difficulty(0) ,imodbits_cloth ],
["british_wellington_bicorne", "Wellington's Bicorne", [("british_wellington_bicorne",0)], itp_merchandise| itp_type_head_armor |itp_civilian|itp_doesnt_cover_hair ,0, 4 , weight(0.5)|abundance(100)|head_armor(8)|body_armor(0)|leg_armor(0)|difficulty(0) ,imodbits_cloth ],
["british_baker_rifle", "Rifle", [("baker_rifle",0)], itp_type_crossbow |itp_merchandise|itp_primary|itp_two_handed|itp_cant_reload_on_horseback|itp_cant_reload_while_moving|itp_next_item_as_melee ,itcf_shoot_musket|itcf_carry_crossbow_back,683 , weight(3.0)|difficulty(0)|spd_rtng(18) | shoot_speed(250) | thrust_damage(100 ,pierce)|max_ammo(1)|accuracy(87),imodbits_none,[]],
["coltcar", "Colt Revolving Carbine", [("colt_carbine",0)], itp_type_crossbow|itp_merchandise|itp_cant_reload_on_horseback|itp_two_handed|itp_primary|itp_next_item_as_melee|itp_cant_reload_while_moving, itcf_shoot_musket|itcf_carry_crossbow_back, 683, weight(3.0)|difficulty(0)|spd_rtng(18)|shoot_speed(250)|thrust_damage(100,pierce)|max_ammo(6)|accuracy(87), imodbits_none ],
["coltcar_melee", "Colt Carbine", [("colt_carbine",0)], itp_has_upper_stab|itp_type_polearm |itp_primary|itp_no_blur|itp_offset_musket,itc_musket_melee|itcf_carry_crossbow_back,180 , weight(3.0)|difficulty(0)|spd_rtng(84) | weapon_length(85)|swing_damage(24 , blunt) | thrust_damage(20 , blunt),imodbits_none ],
["coltrif", "Colt Revolving Rifle", [("colt_rifle",0)], itp_type_crossbow|itp_merchandise|itp_cant_reload_on_horseback|itp_two_handed|itp_primary|itp_next_item_as_melee|itp_cant_reload_while_moving, itcf_shoot_musket|itcf_carry_crossbow_back, 683, weight(3.0)|difficulty(0)|spd_rtng(18)|shoot_speed(250)|thrust_damage(100,pierce)|max_ammo(6)|accuracy(87), imodbits_none ],
["coltrif_melee", "Colt Revolving Rifle", [("colt_rifle",0)], itp_has_upper_stab|itp_type_polearm |itp_primary|itp_no_blur|itp_offset_musket,itc_musket_melee|itcf_carry_crossbow_back,180 , weight(3.0)|difficulty(0)|spd_rtng(84) | weapon_length(85)|swing_damage(24 , blunt) | thrust_damage(20 , blunt),imodbits_none ],
["british_baker_rifle_melee", "Rifle", [("baker_rifle",0)], itp_has_upper_stab|itp_type_polearm |itp_primary|itp_no_blur|itp_offset_musket,itc_musket_melee|itcf_carry_crossbow_back,180 , weight(3.0)|difficulty(0)|spd_rtng(84) | weapon_length(85)|swing_damage(24 , blunt) | thrust_damage(20 , blunt),imodbits_none ],