Section 43 provides:

Trade mark likely to deceive or cause confusion

43. An application for the registration of a trade mark in respect of particular goods or services must be rejected if, because of some connotation that the trade mark or a sign contained in the trade mark has, the use of the trade mark in relation to those goods or services would be likely to deceive or cause confusion.

The trick with s 43 is that the deception or confusion must be caused by something inherent in the mark.  It cannot be as a result of the reputation of some other mark.  In Winton Shire Council v Lomas [2002] FCA 288, Spender J said:

Section 43 is directed to the mark itself. It is not concerned with any deception or confusion caused by the reputation in Australia of some other trade mark. That aspect of the matter is dealt with under s 60.

Similarly, Gyles J said in Pfizer Products Inc v Karam (2006) 70 IPR 599 at [53]:

“Connotation” is a secondary meaning implied by the mark. The likelihood of deception or confusion must flow from the secondary meaning inherent in the mark itself. It is apparent that the underlying purpose of s 43 is a similar purpose to that lying behind ss 52, 53 and 55 of the Trade Practices Act 1974 (Cth). It is to prevent the public being deceived or confused as to the nature of the goods offered by reason of a secondary meaning connoted by the mark in question, rather than, for example, deception by reason of some similarity with other marks…