"apt-mark showmanual" will show you all packages that you have manually installed
"apt-mark showauto" will show you all packages that are automatically installed
"apt-mark showinstall" will show you all the packages that are installed
How is this useful? It tells you what packages are installed in your system.
So you can go "apt-mark showinstall | grep somelibrary" to see if you have a particular library installed that's a dependency.
Vintage Cardco Vic-20, C64, C16, and C128 Parallel Printer Interface Card - New
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Vintage CARDCO Vic-20 C64 +4 C16 and C128 Parallel Printer Interface Card - QTY
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Vintage Microsoft Office 2000 Premium 4 CDs + Product Keys + Service Pack CD
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Intel Pentium A80502-166 Vintage CPU | UNTESTED - READ DESCRIPTION
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ROCKWELL SCIENTIFIC SLIDE RULE 31R CALCULATOR VINTAGE UNTESTED
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Rare Vintage Burroughs Computer Data Processing Tape Approx 2500 Ft
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Vintage 1991 Hewlett Packard DeskJet 500 Printer Manual Bundle W Floppy Disk
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Vintage Fellows 5.25" Multi Media Storage Floppy Disk Tray 90111
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Vintage Retro AT PC Tower - Pentium MMX 166 24MB 3.5 5.25" Sound Keyboard POSTS
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Vintage 1986 IBM 1389262 Model M buckling spring terminal keyboard -1 keycap
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