Understand the report
A report combines several kinds of evidence. Read them together: a file’s type, a component’s declared support, and search metadata answer different questions.
File and Discovery Coverage
File identifies the item you opened. Its UTI is macOS’s name for the type. For example, public.jpeg means JPEG image. The filename ending, such as .jpg, is another clue to the format.
Discovery Coverage lists the starting folders checked, the number of component bundles inspected, and locations that could not be read. A large inventory count does not mean that all those components match your file, or that every component on the Mac was inspected.
UTI Details: how macOS describes the type
This section explains where the type came from and which filename endings and MIME types macOS associates with it. A MIME type, such as image/jpeg, is a format label commonly used when transferring data.
- Declared on this Mac: macOS knows a declaration for the identifier.
- Dynamically generated: macOS generated a
dyn.identifier when no suitable declared type was available. This does not by itself mean that the file is damaged. - Valid identifier, undeclared on this Mac: on macOS 27 or later, the identifier’s spelling is valid, but this Mac has no active declaration for it. Its name alone does not establish its relationships or filename tags.
- Not registered: on macOS 26, the app cannot perform the newer undeclared-identifier validation. It reports the unknown identifier without deciding whether it is valid.
- Invalid or No type identifier available: the identifier is invalid, or no identifier was obtained. Check the resolution evidence before drawing a conclusion about the file.
Resolution evidence lists the clues used, such as the file’s resource type, its filename, Spotlight metadata, or an application’s declaration. The app reads this information; it does not register or change a type.
Physical and functional conformance
Conformance means “is a kind of.” A JPEG is a kind of image. A component that supports images may therefore match JPEG files, even if it does not list JPEG separately.
- Physical conformance describes the item on disk: data, a directory, or a more specific kind of either.
- Functional conformance describes its use: document content, executable content, or an archive.
JPEG image (public.jpeg)
→ image (public.image)
→ data (public.data)
→ content (public.content)Technical detail: reading the tree and graph
UTIs support multiple parent types. The complete relationship is a directed acyclic graph, not necessarily a single tree. The two report views show relevant parts of that relationship. A ↩︎ marker in the text tree marks a shared node; it does not indicate a loop. The graph removes redundant shortcut edges. An empty functional view can mean that the type has no known relationship to the functional bases shown here.
Supertypes are more general types. Preferred extension/MIME tags are the registry’s preferred tags, not a guarantee that the current file uses that filename ending or has valid bytes for the format. Apple’s Uniform Type Identifiers reference.
Spotlight Metadata: information available for search
Metadata is information about a file: its title, type, dates, author, dimensions, and other details. The attributes vary by file and by what macOS can provide. Some files have only basic attributes.
A difference between Spotlight’s type and the resolved file type is highlighted. It is a clue worth checking, not proof that either the file or the index is broken. Likewise, no readable attributes does not prove that the file is unindexed.
Use Full Value… or the value’s copy button to read the complete value.
Technical detail: attribute names and access
Keys such as kMDItemContentType, kMDItemContentTypeTree, and kMDItemContentModificationDate are Spotlight attribute names. The report enumerates available public SDK attributes and qualified custom attributes through MDItem. Private/internal attributes are excluded. The stored kMDItemTextContent and HTML content attributes are write-only; the app does not dump their contents. Search can query indexed text and can separately read text from files you allow it to access.
Readable metadata does not establish that a semantic index is ready, complete, or current. Search and inspection do not force an import or reindex.
Default apps
Default apps (LaunchServices) shows macOS’s registered viewer and editor for the type, plus other registered viewer handlers when available. Viewing and editing are separate roles, so the defaults may differ. An application that opens a document is separate from the component that renders its Quick Look preview.
A missing default means no handler was returned for that role. The inspector reports associations; it does not change them.