Dishwasher and microwave safe. Avoid taking a piece from the fridge straight into a hot oven — thermal shock is the one thing that will crack it. The reactive glaze darkens slightly with use, which is the material behaving normally.
Warm machine wash with like colours, line dry in the shade. Skip fabric softener; it coats the fibre and stops it softening naturally. Warm iron while slightly damp if you want it crisp, or leave it rumpled.
Hand wash in warm water, dry standing on edge so both faces dry evenly. Never put a board in the dishwasher. Re-oil every couple of months with grapeseed or any food-safe finishing oil.
Air it outside rather than washing it — wool self-cleans better than most people expect. When it does need a wash, cold hand wash with wool detergent and dry flat, never hung.
Leave it alone and it will darken to a warm patina. If you prefer it bright, a little lemon and bicarb brings it back.