A list of object flags

STR "pval" . So if the PVAL of an object is 5, it will increase your strength by 5.
INT "pval"
WIS "pval"
DEX "pval"
CON "pval"
CHR "pval"
MANA Mana multipler
SPELL Spell power increase
STEALTH Stealth += "pval"
SEARCH Search += "pval"
INFRA Infra += "pval"
TUNNEL Tunnel += "pval"
SPEED Speed += "pval"
BLOWS Blows += "pval"
CHAOTIC Object has chaotic powers
VAMPIRIC Object has vampiric
SLAY_ANIMAL Object slays animals
SLAY_EVIL Object slays evil monsters
SLAY_UNDEAD Object slays undead monsters
SLAY_DEMON Object slays demons
SLAY_ORC Object slays orcs
SLAY_TROLL Object slays trolls
SLAY_GIANT Object slays giants
SLAY_DRAGON Object slays dragons
KILL_DRAGON Execute Dragon
VORPAL Item is very sharp
IMPACT Cause Earthquakes
BRAND_POIS Object is poison branded
BRAND_ACID Object is acid branded
BRAND_ELEC Object is electricity branded
BRAND_FIRE Object is fire branded
BRAND_COLD Object is cold branded

Traps

AUTOMATIC_5 Trap automatically rearms itself, 1 in 5 failure
AUTOMATIC_99 Trap automatically rearms itself
KILL_GHOST Trap also affects PASS_WALL creatures
TELEPORT_TO After everything else, teleport to player
ONLY_DRAGON Affect only dragons & other AFFECTed creatures
ONLY_DEMON Affect only demons & other AFFECTed creatures
ONLY_ANIMAL Affect only animals & other AFFECTed creatures
ONLY_UNDEAD Affect only undead & others
ONLY_EVIL Affect only evil creatures &c.

More object flags

SUST_STR Sustains strength
SUST_INT Sustains intelligence
SUST_WIS Sustains wisdom
SUST_DEX Sustains dexterity
SUST_CON Sustains constitution
SUST_CHR Sustains charisma
INVIS Invisibility
LIFE Life multiplier
IM_ACID Immune to acid
IM_ELEC Immune to electricity
IM_FIRE Immune to fire
IM_COLD Immune to cold
SENS_FIRE Sensibility to fire
TR2_REFLECT Reflect 'bolts'
FREE_ACT Free Action (player cannot be paralysed)
HOLD_LIFE Hold Life (player cannot have experience drained)
RES_ACID
RES_ELEC
RES_FIRE
RES_COLD
RES_POIS
RES_FEAR
RES_LITE
RES_DARK
RES_BLIND
RES_CONF
RES_SOUND
RES_SHARDS
RES_NETHER
RES_NEXUS
RES_CHAOS
RES_DISEN
SH_FIRE Immolation (Fire)
SH_ELEC Electric Sheath
AUTO_CURSE The object will recurse itself
DECAY Decay
NO_TELE Anti-teleportation
NO_MAGIC Anti-magic
WRAITH Wraithform
TY_CURSE The Ancient Curse
EASY_KNOW Aware -> Known
HIDE_TYPE Hide "pval" description
SHOW_MODS Always show Tohit/Todam
INSTA_ART Item must be an artifact
FEATHER Feather Falling
LITE1 Lite radius 1
SEE_INVIS See Invisible
NORM_ART Artifact in k_info file
SLOW_DIGEST Item slows down digestion
REGEN Item induces regeneration
XTRA_MIGHT Bows get extra multiplier
XTRA_SHOTS Bows get extra shots
IGNORE_ACID Item ignores Acid Damage
IGNORE_ELEC Item ignores Elec Damage
IGNORE_FIRE Item ignores Fire Damage
IGNORE_COLD Item ignores Cold Damage
ACTIVATE Item can be activated
DRAIN_EXP Item drains Experience
TELEPORT Item teleports player
AGGRAVATE Item aggravates monsters
BLESSED Item is Blessed
CURSED Item is Cursed
HEAVY_CURSE Item is Heavily Cursed
PERMA_CURSE Item is Permanently Cursed
NEVER_BLOW Weapon can't attack
PRECOGNITION Like activating the cheat mode
BLACK_BREATH Tolkien's Black Breath
RECHARGE For artifact Wands and Staffs
FLY This one and ONLY this one allow you to fly over trees
DG_CURSE The Ancient Morgothian Curse
COULD2H Can wield it 2 Handed
MUST2H Must wield it 2 Handed
LEVELS Can gain exp/exp levels !!
CLONE Can clone monsters
SPECIAL_GENE The object can only be generated in special conditions like quests, special dungeons, ...
CLIMB Allow climbing mountains
FAST_CAST Rod is x2 time faster to use
CAPACITY Rod can take x2 mana
CHARGING Rod recharge faster
CHEAPNESS Rod spells are cheaper(in mana cost) to cast
FOUNTAIN Available as fountain (for potions)
ANTIMAGIC_50 Forbid magic
ANTIMAGIC_30 Forbid magic
ANTIMAGIC_20 Forbid magic
ANTIMAGIC_10 Forbid magic
EASY_USE Easily activable
IM_NETHER Immunity to nether
RECHARGED Object has been recharged once
ULTIMATE ULTIMATE artifact
AUTO_ID Id stuff on floor
LITE2 Lite radius 2
LITE3 Lite radius 3
FUEL_LITE fuelable lite
ART_EXP Will accumulate
CURSE_NO_DROP The object won’t be dropped
NO_RECHARGE Object Cannot be recharged
TEMPORARY In timeout turns it is destroyed
DRAIN_MANA Drains mana
DRAIN_HP Drains hp
KILL_DEMON Execute Demon
KILL_UNDEAD Execute Undead
TR5_CRIT More critical hits
ATTR_MULTI Object shimmer -- only allowed in k_info
WOUNDING Wounds monsters
FULL_NAME Uses direct name from k_info file
LUCK Luck += pval
IMMOVABLE Cannot move
SPELL_CONTAIN Can contain a spell
RES_MORGUL Is not shattered by morgul fiends (nazguls)
ACTIVATE_NO_WIELD Can be 'A'ctivated without being wielded
MAGIC_BREATH Can breathe anywhere
WATER_BREATH Can breathe underwater
WIELD_CAST Need to be wielded to cast spell from it (if it can be wiekded) */
ONLY_MALE Only usable to males
ONLY_FEMALE Only usable to females
BRAND_LIGHT Light Brand
BRAND_DARK Dark Brand
BRAND_MAGIC Magic brand
SH_ACID Gives a Acid Sheath
SH_COLD Gives a Cold Sheath
BRAND_WATER Water Brand
BRAND_DEATH Death Brand
KILL_VAMPIRE *KILLS* vampires
THROWING Throwable
SENS_COLD Sensitive to cold
CHARGEABLE Chargeable
PROTECTION Protection
ALWAYS_HIT Weapon Always Hits
SENS_ACID Makes player sensitive to acid
SENS_ELEC Makes player sensitive to elec
SAFETY Prevents stuns

ESP defines

This flag allows you to sense these monsters when you are exploring the dungeon. So ESP_ORC allows you to sense all monsters with the ORC flag.

ESP_ORC
ESP_TROLL
ESP_DRAGON
ESP_GIANT
ESP_DEMON
ESP_UNDEAD
ESP_EVIL
ESP_ANIMAL
ESP_THUNDERLORD
ESP_GOOD
ESP_NONLIVING
ESP_UNIQUE
ESP_SPIDER
ESP_ALL