Use the mdimport and mdls commands to dump full information about all the metadata attributes found for a file, and those indexed by Spotlight.
mdimporter
Two significant indexing errors when processing RTF and image files caused search failures. Display in the Finder is also insufficient to make these xattrs as useful as they could be.
The Preview pane in Finder windows can show a comprehensive list of metadata, or a shortened list you can customise in Preview Options. Here’s how to use it and how it can provide further information.
Normally, the x.1 update fixes many of the bugs from the first release. But in Tahoe, a crop of fresh bugs have been included. Here are some of them, and how they have arisen.
In macOS Mojave, Apple changed the way that Spotlight indexes the contents of plain text files. That introduced a bug that prevents indexing of any of the contents of files starting with certain characters. For many Macs, that bug won’t ever be fixed.
Looks at how Spotlight adds a batch of new files to its volume indexes, and how it handles and answers queries.
Apple’s several patents cast new light on how Spotlight indexes the metadata and contents of local files, and why mds and other processes need to reindex periodically.
How Spotlight works, Core and global Spotlight, importing failure, exclusions from indexing, re-indexing, excessive re-indexing, failure to find, iCloud Drive and network shares.
You use Spotlight to search for something you’re sure is there, but it can’t find it. Here are some methods to discover why that search failed.
Immediate actions to get the best result from your search, and how to tackle even the most deep-seated of Spotlight problems.
The Eclectic Light Company 