Up until the 1960s, Catholic schools throughout most of the English-speaking world were dominated by members of religious teaching orders, including female religious. For over a century following their establishment in 1866, one of the most prominent female religious teaching orders in Australia was that of the Sisters of St Joseph of the Most Sacred Heart of Jesus. The first part of this paper contextualises the emergence of this particular religious order in terms of the development of Catholic education internationally and in Australia, and the associated "religious formation" of nuns as teachers. Part two is centered on the most significant text used to guide the "religious formation" of members of this order both as religious and as teachers, namely, that of their "rules and customs". Drawing on an analytic approach based on a theory of social semiotics, it analyses both the sets of practices and the textual mechanisms through which the identity of members of the order as teachers was constructed. (Contains 57 footnotes.)