Unknown items

Warcraft Logs names the items a player wore only by id. Everything the audits know about an item — its resistance, its sockets, whether it takes an enchant, its item level — comes from an offline copy of the TBC item database (the same one the wowsims simulators use), plus a hand-kept list of items that copy predates. When an id is in neither, the engine says so instead of guessing.

What you see#

• Shadow resistance: the note Unknown items: [278774, 278819] on the player's row. The item counts for zero resistance until it is known, so the player's Gear SR may read lower than it is.
• Enchants & gems: an unknown item is not asked for sockets or an enchant it may have, so a slot can pass that should not.
• Any audit: an unknown enchant effect on a known item behaves the same way.

The engine never invents a value. A low number with an Unknown items note beside it is "not yet known", not "bad gear".

Why it happens#

Anniversary realms add items the original TBC data never had — the anniversary-only cloaks and trinkets, the vendor and reputation pieces, occasional renamed drops — and the offline copy was built from the original game. Every one of those items has to be added by hand once; after that it is known to every report.

How an item gets added#

1. Every audit records the ids it could not name. The site's admin sees them on the analytics page under What the engine could not name, by frequency, each with a Wowhead link — so the item that half the raid wears rises to the top.
2. The item's record (name, quality, item level, slot, resistances, sockets, whether it takes a random suffix) is added to the extra-items list in the site's data. The wowhead lookup tool in the source tree writes the record in the right shape.
3. The next deploy knows the item, and every audit — past reports included, since they are recomputed from the cached log — shows the right number.

Nobody has to report it for the process to start, but the flag icon beside a player's name (with a note saying which item) is the fastest way to have a specific one looked at.

Estimated greens are different#

A green "of Shadow Protection" piece the engine has never seen is not unknown — its slot and item level are enough to estimate the suffix's resistance by interpolating between known greens of the same slot. The note reads Estimated green suffix value: … and the number is usually within a couple of points. See How shadow resistance is computed.