Sub-section 44(4) of the TMA provides an exception to the grounds of opposition provided by ss 44(1) and (2) where there has been continuous use of the applicant’s mark from before the priority date of the cited mark through to the priority date of the applicant’s mark.
Note that the exception provided by s 44(4) is subject to s 58A (as to which see here) and (in practice at least) to ss 58 and 60.
While sub-section 44(3) is unequivocally subject to s 60 TMA (McCormick & Co Inc v McCormick (2000) 51 IPR 102 per Kenny J), there is no equivalent superior court authority in respect of s 44(4). It is arguable that s 44(4) is different because (unlike s 44(3)), it states in mandatory terms that if the elements of the subsection are met, the Registrar “may not reject the application because of the existence of the other mark”.
In Roger Maier v Asos plc  ATMO 7, Hearing Officer O’Brien said:
The application of the provisions of subsection 44(3) is at the Registrar’s discretion. There is no such discretion with respect to subsection 44(4). If the Registrar finds that there has been prior continuous use of a trade mark in relation to the similar/closely related goods or services the application cannot be rejected, or, as in the present matter, registration refused.
In Fairmont Hotel Management LP v Schwartz Family Co Pty Ltd (2014) 108 IPR 339, however, Hearing Officer Thompson set out the following passage from Justice Kenny’s decision in McCormick:
 As counsel for McCormick & Co observes, the structure of the Act and the provisions with which this appeal is concerned differ markedly from the 1955 Act. Parts 4 and 5 of the Act relate to separate stages in the registration process. The reasoning that led Mason CJ, Dawson, Toohey and Gaudron JJ to hold that s 28 was subject to s 34 of the 1955 Act does not apply under the new Act. Within Division 2 of Part 4, s 44(1) provides for a ground for rejecting an application before acceptance by the Registrar. Subsection 44(1) expressly states that it is subject to s 44(3), the honest concurrent user provision. The whole of s 44 is expressed as an interlocking series of subsections. Section 60, which is part of a Division specifically setting out the grounds for opposing registration, is directed to the position after acceptance. Section 60 is not expressed to be subject to s 44(3), any analogous limitation, or even the Act generally: contrast s 89(1). On its face, it is a stand-alone provision. Furthermore, s 60 is apparently intended to afford a ground of opposition that is additional to the grounds set out in Part 4. Section 57 expressly states that the grounds of opposition may be “any of the grounds on which an application for the registration of a trade mark may be rejected under Division 2 of Part 4” (which includes s 44). Sections 58 to 62 add further grounds for opposition. On its face, there is no honest concurrent user exception to s 60. [Emphasis added by Hearing Officer Thompson.]
Mr Thompson concluded:
It must follow, in applying the above principle, that if s 44(3) does not provide an exception to s 60, then neither does s 44(4). Kenny J’s comment which I have stressed, above, indicates that s 60 is also not subject to 58. It is therefore possible for an applicant to show that it is, in effect, the owner of a trade mark via its prior use under s 44(4) or via s 58 and yet have it found that the reputation of an opponent’s trade mark is such that the use of the applied-for trade mark would confuse and deceive because of the greater reputation of the opponent’s trade mark. Accordingly, at the very least, the effect of the interaction of ss 60 and 44(4) is such to encourage the early registration of trade marks.