We can argue about a few of these, but most of them should not be present in Mainland. See also https://www.tamriel-rebuilt.org/bugtracker/references-standard-objects-m...

Script TR_m3_OE_Phyrious_sc references katana_bluebrand_unique
Script TR_m3_q_guardcall references katana_bluebrand_unique
Npc TR_m1_Gona_Veloth references expensive_amulet_aeta
Npc TR_m1_q_Gona_Veloth_D references expensive_amulet_aeta
Npc TR_m2_Adrend Salas references common_glove_l_moragtong
Npc TR_m2_Eifid references common_glove_r_moragtong
Npc TR_m2_Finera_Hloran references common_ring_01_mgbwg
Npc TR_m2_Garer_Llenas references common_glove_r_moragtong
Npc TR_m2_Nethyn Veroth  references common_glove_l_moragtong
Npc TR_m2_O_Fistirne references ember hand
Npc TR_m2_Vilval Nerethi references common_glove_l_moragtong
Npc TR_M3_Drelyne Fareloth references common_glove_l_moragtong
Npc TR_m3_Juvol_Gols references common_glove_l_moragtong
Npc TR_m3_TT_IlleneAssa01 references common_glove_l_moragtong
Npc TR_m3_TT_IlleneAssa02 references common_glove_l_moragtong
Npc TR_m3_TT_IlleneAssa03 references common_glove_l_moragtong
Npc TR_m4_Kolum  references steel_gauntlet_left_ancient
Cell Sea of Ghosts Region references ex_co_ship_trapdoor
Cell Gol Mok references hlaalu_loaddoor_ 02_balyn
Cell Andothren references barrel_01_ahnassi_drink
Cell Andothren, Docks references crate_02_Lagius
Cell Andothren references com_basket_arille's
Cell Alumawia, Shrine references misc_com_silverware_fork_uni
Cell Azurranu references bk_galur_rithari's_papers
Cell Dun Akafell, Forsaken Manor, Basement references de_p_chest_02_adibael
Cell Dun Akafell, Forsaken Manor references barrel_01_manicky
Cell Akamora, Guild of Mages references de_r_chest_01_cienne1
Cell Erethan Plantation, Storage Shack references barrel_01_ahnassi_drink
Cell Akamora, Mining Head Office references ember hand
Cell Dun Akafell Canals references Inviso_wall_10
Cell Necrom, Lesser Bonewalker Smithy references ingred_gold_kanet_unique
Cell Necrom, Northern Watchtower references chest_small_mororurg2
Cell Necrom, Catacombs: Temple Entryway references bonemold_tshield_hrlb
Cell Necrom, Catacombs: Depths references Redoran_treas_chest_01
Cell Necrom, Waterfront references barrel_01_ahnassi_drink
Cell Necrom, Tenandus' Rare Books references de_r_chest_01_arobar03
Cell Meralag references EX_MH_door_02_ignatius
Cell Baan Urlai references de_p_chest_02_dralor
Cell Romithren Monastery, Chapel references misc_lw_bowl_chapel
Cell Romithren Monastery, Library references misc_lw_bowl_chapel
Cell Romithren Monastery, Scriptorium references misc_lw_bowl_chapel
Cell Seitur, Odrothi Indus' House references bonemold_founders_helm
Cell Tharonen Manor references crate_01_medernulen2
Cell Evos, Blacksmith references crate_01_vivec_fg
Cell Necrom Lighthouse, Entrance Hall references bk_galur_rithari's_papers
Cell Necrom Lighthouse, Sanctuary references Active_MH_Forcefield_01
Cell Sevadartus references crate_01_tmtower
Cell Llothanis, Bal Gernak's Manor references de_r_closet_01_rothan
Cell Ruinous Crypt references Inviso_wall_7
Cell Sagea references barrel_01_ahnassi_food
Cell Tel Aranyon, Upper Tower references de_r_chest_01_arobar03
Cell Ranyon-ruhn, Nataya Radasar's House references Com_Basket_01_chargen
Cell Ranyon-ruhn, Drelatha Nidresa's House references Com_Basket_01_chargen
Cell Zainna references com_basket_01_pierlette
Cell Dral's Sanctum, Heaven's Abyss references Inviso_wall_10
Cell Tel Muthada references crate_01_anruin
Cell Marog, Tel Onoria: Lord Athyrion's Chambers references de_r_drawers_01_ondres
Cell Bthangthamuzand, Factory references Inviso_wall_1
Cell Old Ebonheart, TEM Princess Morgiah references Com_Chest_11_pellecia a
Cell Old Ebonheart, Hastophos Velifer's House references chest_small_mororurg
Cell Old Ebonheart, Southern Watchtower references Com_Chest_11_pellecia a
Cell Old Ebonheart, Bridge Towers references barrel_01_manicky
Cell Old Ebonheart, Anjzhirra's Rare Goods references com_chest_02_v_clanler
Cell Old Ebonheart, Hamal's Redguard Goods references barrel_01_manicky
Cell Old Ebonheart, Imperial Navy Command Post references chest_small_02_seleth
Cell Old Ebonheart, Imperial Navy Command Post: Tower references com_chest_01_alfhedil
Cell Old Ebonheart, East Empire Company references com_chest_02_thendas2
Cell Old Ebonheart, East Empire Company: Basement references chest_small_02_nalcarya
Cell Old Ebonheart, East Empire Company: Offices references chest_small_02_yngling
Cell Old Ebonheart, Ruma Soanix's Manor references chest_small_02_nalcarya
Cell Old Ebonheart, Merxia Vendicci's Manor: Basement references barrel_01_ahnassi_food
Cell Old Ebonheart, Nirungaer: Woodworker references furn_com_rm_bookshelf_02_huleen
Cell Old Ebonheart, Otrebus Delagia's House references expensive_ring_aeta
Cell Old Ebonheart, Western Watch Barracks references barrel_01_ahnassi_food
Cell Ebon Tower, Lower Gateway Tower references barrel_01_ahnassi_drink
Cell Dondril references barrel_01_ahnassi_food
Cell Ilvi Ancestral Tomb, Depths references racerbeak
Cell Ilvi Ancestral Tomb, Urn Chamber references chest_Andrano01
Cell Vys-Assanud references barrel_01_ahnassi_drink
Cell Vys-Assanud, Caved-in Mine references de_p_chest_02_adibael
Cell Dassur-Kur Lookout references barrel_01_ahnassi_drink
Cell Passur-Sur Lookout references Light_logpile_UNI
Cell Bthungtch, Halls of Resonance references dwrv_endusal_desk01
Cell Aren Manor, Guardhouse references barrel_01_ahnassi_drink
Cell Aren Eggmine references barrel_01_ahnassi_drink
Cell Napali references chest_01_v_bildren
Cell Roa Dyr, Black Hand Hall references common_glove_l_moragtong
Cell Almas Thirr, Hall of Tribute references de_r_chest_01_arobar03
Cell Almas Thirr, Indoril Garrison, Quarters references de_p_chest_02_meldor
Cell Khalaan, Swallowed Passages references in_sotha_mon_mach
Cell Verulas Pass, Tunnels references active_velothi_altar_Mephala
Cell Necrom, Fane of the Ancestors: Vault references bk_galur_rithari's_papers
Cell Firewatch, Wall Towers references barrel_01_ahnassi_drink
Cell Firewatch, Drakelight Beacon references crate_01_syloreia
Cell Firewatch, Destarmion: Jeweler references expensive_ring_aeta
Cell Helnim, Gate Towers references misc_com_metal_plate_07_UNI2
Cell Firewatch, Gorinia's House references barrel_01_ahnassi_drink
Cell Forlorn Shipwreck, Upper Level references misc_clothbolt_02_uni
Cell Andothren, Sathes Barnalo's House references misc_com_bucket_boe_UNI
Cell Andothren, Guild of Fighters references amulet of verbosity
Cell Andothren, Morag Tong Guild references barrel_01_ahnassi_food
Cell Andothren, Ulran Teryon: Fine Weaponsmith references de_r_drawers_01_hlaalo
Cell Andothren, Torasa Fols' Apartment references misc_com_wood_spoon_01_UNI2
Cell Andothren, Council Club: Basement references barrel_01_ahnassi_drink
Cell Iliath Monastery, Dormitory references misc_lw_bowl_chapel
Cell Llaram Plantation, Manor references de_p_closet_02_andral
Cell Suldunanit references Com_Basket_chargen2
Cell Llendu Ancestral Tomb references bonemold_gah-julan_hhda
Cell Assinad references de_r_chest_01_darius
Cell Savrethi Distillery, Savrethi Manor references misc_com_wood_fork_UNI1
Cell Berendas Ancestral Tomb references amulet of infectious charm
Cell TR_RR_unused_Monastery references misc_lw_bowl_chapel
Cell Bodrum, Tuvenie Mels' House references misc_com_wood_fork_UNI2
Cell Kurhu references chest_tomb_gladroon3
Cell Shan-Ahhe references de_p_chest_02_adibael
Cell Armun Pass Outpost, Bala Dralor: Outfitter references barrel_01_cheapfood_co
Cell Armun Pass Outpost, The Guar With No Name references barrel_01_ahnassi_drink
Cell Issarbaddon references de_p_chest_02_arynioret
Cell Verenabi, Lower Caves references de_r_chest_01_arobar03
Cell Arvud, Hlavora Tilvur: Trader references de_p_chest_02_arynioret
Cell Arvud, Western Guard Tower references de_p_chest_02_meldor
Cell Yanashpi, Upper Level references com_sack_01_colony
Cell Yanashpi, Lower Level references misc_com_wood_fork_UNI1
Cell TR_VelothiMtn_Cave_6 references dwrv_chest_fals
Cell TR_VM_Cave_5 references BM_misc_skull_griss