BANs are unique in that names are assigned for combination preparations as well as single-drug preparations. For example the BAN Co-amoxiclav is assigned to preparations containing amoxicillin and clavulanic acid. Most other pharmacopoeias simply refer to combination products by both ingredients in the preparation, in this example "amoxicillin with clavulanic acid".
This has resulted in an interesting situation in countries such as Australia. While the British Pharmacopoeia and BANs are the official pharmacopoeia/names defined by legislation in these countries, the former-BANs continue to be used, purportedly because of the difficulty of changeover. Despite the importance of the BP there appears to be little or no movement in the direction of changing these names.