In addition to what's approved in my EDC and PSK kits, I carry a metal ball-point pen and a cork-backed, 12-inch metal ruler.
I also carry a coarse, folding DMT sharpening stone and twenty or so feet of paracord. If the paracord becomes contraband, I'll start carrying a roll of electrical tape.
On my keychain is an LED flashlight, a whistle, and a BSA metal match. In a capsule I carry some personal meds cushioned by lots of cotton balls.
I think these give me a good start on the basics.
Bear
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No fire, no steel.