Only six files out of tens of thousands searched. They’re supposed to be compressed, but aren’t. And nothing has been near them that might have done that. So why and how did this happen?
xattr
Soon after introducing iCloud and iCloud Drive, Apple changed the way most metadata was handled to ensure it was synced up to the cloud. Recently this has been reversed, and little metadata is now synced. Was this an accident or intentional? What is the workaround?
Traces the path of metadata from inside a PDF document and its extended attributes, to those in Spotlight’s indexes and displayed in the Finder. Only a third survived that journey.
A summary of iCloud Drive syncing of attributes, data, extended attributes, document versions (complex), Spotlight index content, and QuickLook previews.
What happens when you move a file with metadata attached in extended attributes to iCloud Drive? Which of those are preserved when you access that file from another Mac?
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.
How to select the most appropriate way of storing metadata, limitations of Finder Comments and Tags, which extended attributes are best, and which utilities to edit and manage them.
A simple and accessible way of categorising folders, they’re stored as extended attributes, and robust. They work best with up to 7 categories, but can confuse with many different text labels.
Although easy to add to documents, Finder comments work strangely, and can prove fragile. They can also be used to conceal malicious code by steganography, but there are better options.
Introduced in Mac OS X 10.4 to extend resource forks, they have flourished since. Explains their storage, how they persist or don’t, with an appendix explaining their flags.
The Eclectic Light Company 