Examples of these include some sleep aid tablets such as Nytol, human deworming tablets such as Mebendazole, painkillers with small amounts of codeine (up to 12.8 mg per tablet), and pseudoephedrine. Medication available only with a prescription is marked somewhere on the box/container with Pharmacy-only products are marked with [P. A prescription is not required for medicines, and pharmacy sales assistants are required by Royal Pharmaceutical Society codes to ask certain questions, which varies for what the customer says. If they ask for a specific product, the pharmacy assistant must ask "Who is it for," "How long have you had the symptoms," "Are you allergic to any medication," "Are you taking any medication" ('WHAM' questions). If a customer asks for a remedy, e.g., hay fever, then the two WHAM questions must be followed "Who is it for," "What are the symptoms," "How long have you had the symptoms," "Have you taken any action towards your symptoms," and "Are you taking any other medication." It is with this information that the pharmacist can halt the sale, if need be. No [POM, or [GSL products that are stocked in a pharmacy can be sold, dispensed, or pre-made until a responsible pharmacist is signed in and on the premises. Some medication available in supermarkets and petrol stations is sold only in smaller packet sizes. Often, larger packs will be marked as and available only from a pharmacy. Frequently, customers buying larger-than-usual doses of [P medicines (such as DXM, promethazine, codeine or Gee's linctus) will be queried, due to the possibility of abuse.