A Caveat or Warning for Common Cursitors, vulgarly called vagabonds was first published in 1566 by Thomas Harman, and although no copies of that edition survive, it must have been popular, because two printers were punished by the Stationers' Company in 1567 for pirated editions. Two editions were published in 1568, and a revised edition in 1573. It is one of the fundamental texts for rogue literature. Harman is one of the first writers to use the word rogue, which was adopted in the Poor Law legislation of 1572.
Harman claimed to have collected his material direct from interviews with vagabonds themselves. The Caveat contained stories of vagabond life, a description of their society and techniques, a taxonomy of rogues, and a canting dictionary, which were reproduced in later works. Harman’s reputation has changed since his work was first republished in the early twentieth century; A.V Judges described him then as having "all the deftness of the trained sociologist", and the Caveat has been used as a primary source. However, historians have long doubted the reliability of his accounts of vagabond society and the use of cant. Harman has been subject to literary analysis informed by Marx, Freud and Foucault, although it has been suggested these "appear to be fruitful sources of fertile error" (Beier).
Harman was certainly not a neutral observer; he frequently makes explicit moral and social judgement about his subjects. These reflect a society in which sexual incontinence was subject to penalties in the local manor courts, the church courts and by Justices of the Peace in Quarter Sessions. It was also a society in ferment over the appropriate response to the increasing number of "masterless men". A large part of the Caveat was included in William Harrison's Description of England as part of Holinshed's Chronicle. Harman influenced and justified the legal punishment of vagrants, particularly the 1572 Vagabond Act. It was Harman’s characterization of vagrants that influenced Elizabethan perspectives on them.