Yup, thornproof, waterproof, mudproof, grime proof, proof of pretty much everything. I remember one tale of a Barbour being dredged up from a harbour after several months to a year under salt water and still being completely wearable. I used to say that the Brits are masters of 19th century technology, but most people didn't get it, lol. The real beauty is that the stuff is breathable.
I too had a snap in liner, however it went missing during my last move, hopefully will still turn up but meantime I have vests and gilets, etc. Could never get the Barbour hood to stay attached (short of stitching it on) and didn't like it anyway, so I settled for the very crushable waxed cotton bucket hats they sell, stow in a pocket until needed. No point in having a rain parka if your head and neck are exposed and getting wet.
Or for the jaunty equestrian look, lol: