Time for my usual explainer on this.

Travellers have a ticketed weight and piece limit, which as that suggests is shown on the e-ticket, which may for example show 2PC 23KGS. Two bags checked, up to 23 kgs per bag. On Basic fares it is zero, and status won't help on BA operated services, but may well help on other airlines such as Iberia and AA.

Then there are extra allowances which may not show on the ticket, due to status or product offering, which are communicated to check-in staff. So a gold card may get you more than the ticketing amount, as one example, and in this case 32 kgs. So the Iberia/AA aspect mentioned above may not be on the ticket but in practical terms you can check in a bag.

Formally the e-ticket is contractural, but in reality it can be more than the e-tciket.

Finally cabin or hand luggage is also stated in the e-ticket, that tends not to vary and BA aren't too fussy about rigid adherence to the cabin baggage allowance.