In his 1958 poem 'Dedication to my Wife' TS Eliot proclaims "these are private words addressed to you in public". Simultaneously written for his wife, Valerie Fletcher, and to the implied you of a discourse network, Eliot's poem helps to illustrate the narrative voices and silences that are constitutive of an intimate public sphere. This paper situates reciprocity as a condition of possibility for public privacy. It shows how reciprocity is enabled by systems of code operating through material and symbolic registers. Code promises to control communication, to produce neutral, systemic forms of meaning. Yet such automation is challenged by uneven and fragmented patterns of reciprocity. Moreover, examining the media of public privacy reveals historical trajectories important for understanding contemporary socio-technical platforms of reciprocity. To explore the implicit requirement of reciprocity in publicly private practices, three sites of communication are investigated framed by a media archaeology perspective: postal networks, the mail-art project PostSecret and the anonymous zine 'You'. Keywords: Public privacy, reciprocity, epistolary, postal networks, access, control, code.