Co-authorship between doctoral students and their supervisors is a mostly occluded practice, generalised according to the candidates' disciplines. There is limited understanding of the practice, particularly in humanities, arts, and social sciences (HASS) disciplines. This study explores HASS doctoral students' and supervisors' perceptions towards co-authorship during candidature. Focus is given to participants' motivations, perceived challenges, and reservations about engaging in supervisor-candidate co-authorship. Surveys of 121 doctoral students and 126 supervisors representing 12 HASS disciplines across 18 Australian universities revealed divergent interpretations of co-authorship: although many viewed it as a collaborative process, more than a third of supervisors approached it through the lens of 'divide and conquer'. Such findings raise important ethical and pedagogical concerns, highlighting the need for clearer terminology and guidelines. We respond to this ambiguity by proposing a new term, 'collaborative co-authorship', reconceptualising supervisor-candidate co-authorship in a way that clarifies perceptions towards the practice and presents it as a pedagogical approach to apprentice doctoral students to become fully-fledged academics. It is our hope that this reconceptualisation will equip stakeholders at individual, institutional, and national levels to engage more confidently and intentionally with collaborative co-authorship through PhD candidature.