Items are missing related_items while their own variants are grouped without them

[alistair3149]

The problem

Items are missing related_items while other members of the same product line have it, and in some cases while those members are grouped under a set named after the missing item.

The five CSP-68L Backpack items:

item	set_name	base_item
CSP-68L Backpack	null	null
CSP-68L Backpack Cayman	"CSP-68L Backpack"	present
CSP-68L Backpack Epoque	null	null
CSP-68L Backpack Forest Camo	"CSP-68L Backpack"	present
CSP-68L Backpack Night Camo	"CSP-68L Backpack"	present

Three of the five are grouped into a set called "CSP-68L Backpack". The item actually named CSP-68L Backpack is not one of them, and neither is Epoque.

The same shape appears one level up, across the L/M/H line: CSP-68L Backpack has nothing while CSP-68M Backpack and CSP-68H Backpack are both populated, despite an identical class-name shape (cds_combat_{light,medium,heavy}_backpack_01_01_01).

Scope

To exclude types that legitimately have no variants — seats, cargo, internal vehicle components and so on — this counts only items inside types that are at least 80% covered, where the absence stands out against the type's own norm.

76 items are ungrouped while a differently-named sibling of the same type and product line is grouped. A sample across types:

ungrouped item	grouped sibling	sibling's set_name
CSP-68L Backpack	CSP-68L Backpack Cayman	"CSP-68L Backpack"
ADP-mk4 Helmet Woodland	ADP-mk4 Helmet Big Boss	"ADP-mk4"
Chiron Backpack Heartthrob	Chiron Backpack	"Chiron"
BUL-H4 Armor Stronghold	BUL-H4 Armor	"SuperHeavy"
Carnifex Armor Lucky Break	Carnifex Armor Core	"Carnifex Armor"
Arcus Gloves Gray	Arcus Gloves Brown	"Arcus Gloves"
Prim Shoes	Prim Shoes Aqua	"Prim Shoes"
300 Series Amber Wave Paint	300 Series Citron Paint	"300 Series"

Note this is not a claim about the overall 41% of items that carry no grouping data. Most of that looks correct — plenty of types genuinely have no variants. It's specifically the items whose own siblings are grouped without them.

Method

Full sweep on 18 September 2026 — the list endpoint accepts the include, so no per-UUID fetching is needed:

GET /api/v2/items?limit=200&page=N&include=related_items&locale=en_EN

62 pages, 12,331 items, no duplicate UUIDs. Restricted to the 24 types with at least 30 items and at least 80% grouping coverage, then matched ungrouped items against same-type siblings sharing a name stem, excluding items that merely share an identical name.