How the quarantine flag for apps and that for docs opened in sandboxed apps differ, and why there are now so many quarantine flags to trip us up.
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Have you noticed quarantine flags appearing on movies and PDFs which have never been downloaded? Here’s a possible explanation.
Later this year, in macOS 10.15, one of the media types which will become unsupported is JPEG 2000 still images. Here’s how to find and convert your old images.
Three ways to remove data from PDFs: redaction, deletion of content, and deletion of annotations. Can you trust them, or do they leak data?
Can you get malware in PDF? How far can you trust a PDF, or could it be a forgery? How to sign PDFs, and what data may remain hidden inside them.
Why don’t some PDFs display properly outside Adobe software? Will PDFs ever become more accessible? And what to do when they get damaged?
A close look at just what macOS PDF support and Preview can do well, including a hidden file conversion feature.
Getting the best out of Quick Look’s document previews and thumbnail icons, in the Finder and the Open File dialog.
Four versions of the same app to demonstrate different app states in Sierra and High Sierra, and how your apps can join the undead.
The odd behaviour of some apps, which quit on their own, but hang around as zombies, and the long battle trying to make sense of logs.
The Eclectic Light Company 