This archive tracks four layers. A record present in 1 of them (M41) is silent in the rest, and says so.
The Horus HeresyM30–M31
[RECORD LOST]
No record for this location in The Horus Heresy.
Age of the ImperiumM32–M40
[RECORD LOST]
No record for this location in Age of the Imperium.
The 41st Millenniumpre-Rift
contested
Imperial mining world overrun by the Orks of Warboss Killzkar, 926.M41
A mining world of the western Ultima Segmentum near Catachan and Ryza whose cities lie in a vast cavern network. When Waaagh! Grax invaded the Ryza System in 925.M41, every Imperial world within ten light years had to raise extra regiments, and Dulma'lin drafted 80% of its people to meet the tithe, which left it open to invasion. By 926.M41 the Orks of Warboss Killzkar hold its capital, and in Straken the Catachan II under Colonel 'Iron Hand' Straken are sent in to sabotage the Ork war effort ahead of an armoured invasion by the Selvian Dragoons: the campaign Lexicanum calls the Dulma'lin Cleansing. How it ends is in the book's spoiler.
Era Indomituspost-Rift
[RECORD LOST]
No record for this location in Era Indomitus.
Position
Map frame: 689.55, 460.89 in the archive's 0–1000 disk space (core at 500, 500).
Distance from the core: 194 units ≈ 20.6k light years, east of the galactic core.
Height above the disk plane: -7.7 units — invented thin-disk jitter, deterministic per record. No published source gives any location a z coordinate.
System: Dulma Lin System
Books set here
1 title in the reading tracker touches this record, 1 of them as a primary location. Titles link out to the tracker.
Every fact in this record, and where it came from. Editorial derivations say so.
identityhigh
wh40k.lexicanum.com/wiki/Dulma'lin (read directly in a browser on 2026-10-02): 'a world of the Imperium that lies in the western Ultima Segmentum near the planets Catachan and Ryza' (Codex: Imperial Guard 5th edition, pgs. 26-27, the 'A Galaxy of War' map); the Dulma'lin Cleansing of 926.M41 by the Catachan II under Colonel Straken (pg. 23). https://wh40k.lexicanum.com/wiki/Dulma'lin_Cleansing (citing the novel with the Codex and White Dwarf 357): the campaign 'mainly occurred in the Ork-infested cavern network of the planet'. Black Library's description on https://wh40k.lexicanum.com/wiki/Straken_(Novel): 'the cavern world of Dulma'lin'. Corroborated by Lexicanum Straken, Snikrot, Sly_Marbo, Greiss and Selvian_Dragoons, each citing the novel. NAME-COLLISION CHECK: no other index record uses the name; 'dulan' and 'dulcis' are different worlds.
classlow
editorial: 'forge', this dataset's industrial-extraction palette, because the only descriptions published are 'mining planet'/'Mining world' (Lexicanum Straken, Snikrot, Sly_Marbo, Selvian_Dragoons) and 'cavern world' (Black Library), with the infobox Class field empty and no terrain, climate or colour word for the surface. The belmos-vii and piscina-iv precedent for a mining world. 'hive' refused (no hive is named; the capital is a city with vast gates), 'dead' and 'desert' refused (nothing describes a barren surface).
segmentumhigh
wh40k.lexicanum.com/wiki/Dulma'lin infobox: Segmentum 'Ultima Segmentum', category Ultima Segmentum; 'in the western Ultima Segmentum' (Codex: Imperial Guard 5th edition, pgs. 26-27). Sector and System are blank.
gposlow
inferred: canon publishes no coordinate, only neighbours: 'near the planets Catachan and Ryza' on the Codex map, and Lexicanum's statement that Dulma'lin was among 'all Imperial worlds within 10 light years' of the Ryza System when Waaagh! Grax invaded it in 925.M41 (Codex: Imperial Guard 5th edition, pg. 22). Ryza is the tightest anchor, so the world is set one unit from ryza [690, 460] along the unit vector toward catachan [600, 640], (-0.4472, 0.8944), at [689.55, 460.89]: westward, as 'western Ultima' and the Catachan neighbour suggest. THE MAGNITUDE IS A RENDERING MINIMUM, NOT THE CANON FIGURE: ten light years is 0.09 units at this frame's 106.4 ly per unit, which would put the two markers on top of each other; one unit is the elysia precedent (Elysia is one unit from Armageddon for a canon thirty light years). The BEARING is editorial (the Codex map image was not read); only the neighbourhood is canon. Both anchors' own positions are low-confidence derivations. Nearest other marker Chemos at 5.8 units. Z -7.7 is the zPolicy value (compute-z.mjs dulma-lin 689.55 460.89).
erashigh
m41 only: the campaign is dated 926.M41 (Lexicanum Dulma'lin_Cleansing; Dulma'lin, Codex: Imperial Guard 5th edition, pg. 23), and the shelf files Straken M41 — Pre-Great Rift. Allegiance 'contested': an Imperial world held by Killzkar's Orks for the whole of the book. The outcome, and Lexicanum's later events (928.M41, Codex: Astra Militarum 6th edition; infobox 'Unknown, formerly Imperium'), are kept out of the era summaries because they give away how the Cleansing ends; hh, aoi and indomitus carry nothing.
no-system-surveyhigh
NO systems/dulma-lin.json IS AUTHORED, although Dulma'lin is Straken's PRIMARY setting: canon publishes no star, no system name, no sibling body and no ordinal (Lexicanum's System field is blank and the name carries no numeral, unlike Belmos VII or Kalidar IV), so a survey would be wholly invented. The khorsari-reach-worlds precedent. The map's synthesiser draws the world from its class and seed = hashId('dulma-lin') % 97. systemId 'dulma-lin' is the world's own name. UPGRADE CANDIDATE if a permitted page names its star or system.