Results for label
typo3_label_lookup
Reads labels from the installation. Where it cannot be booted the tool reads the package files instead and says which labels that leaves out.

Reading the package registry when the installation will not boot
The fallback returns every declared entry — labels among them — and none of the dynamically registered ones. The shortfall travels with the result.

Label overrides resolve before the extension is loaded
A label defined in TypoScript and overridden by an extension now resolves in the order the core documents, which changed in 13.4.
reference Documentation · Toolstypo3_icon_lookup
Returns the identifier the core itself uses. The label of an icon is not part of the answer — identifiers are what the registry holds.
What was searched
Four sources, and the last of them is your own installation — which is searched only where one has been reached. A facet that says zero has been asked; a facet that is missing was never available.