This essay brings to light the most substantial episodes of textual scholarship on Piers Plowman to have occurred over the space of 300-odd years, of which one certainly, the other likely, took place in the household of Archbishop Matthew Parker. The former consists of a series of red numbers inscribed next to lines in two passus of the C-version copy Cambridge, Corpus Christi MS 293, which are shown to refer to the pages on which the equivalent lines appear in a sixteenth-century printed edition of Piers B, reflecting careful comparison of their respective texts. The latter is manifested in the 'correction' of a portion of the C-text manuscript London, British Library, MS Royal 18 B xvii so as to bring it into line with its equivalent in a printed edition of B. The placement of the lines is suggestive of access by the corrector to unbound printed matter. This episode, so it is argued, is most intelligible in the context of such episodes of correction as that in which John Joscelyn, Parker's secretary, engaged. A sub-theme of the essay is that Stephan Batman's putative centrality to the topic of the Parkerian Piers is not supported by any evidence.