Slave law in early America may be found in the formal written laws created in metropolitan places such as Paris or Madrid as well as locally within English colonies such as Barbados or South Carolina. These written laws constitute only one portion of the known law governing slave behavior, for individual masters created their own rules to restrict enslaved persons. These master-made rules of conduct almost never appear in print and were conveyed most often through oral transmission. Such vernacular laws provide another element of the limitations all enslaved people experienced in the colonial period. Those without literacy, including Native Americans or illiterate settlers, nonetheless had rules to limit slave behavior, even if they remained unwritten. Customary law, Bible precepts, and Islamic law all provided bases for understanding the rules that bound unfree persons. Most colonial law mandated barbaric punishments for slave crime, though these were sometimes commuted to banishment. Spanish and French codes and local ordinances did not always agree on how slaves should be treated. The numerous laws found in English colonies, sometimes wrongly denominated as codes, spread widely as individuals migrated; the number and variety of such laws makes comprehensive transimperial comparisons challenging. Laws might occasionally ban keeping slaves or trading in them, but most such laws were ignored. Slave courts typically operated in arbitrary, capricious ways that assumed slave guilt and accepted weak evidence to prove it. Runaways might, if they joined strong maroon communities (bands of runaways living together), end up enforcing the laws against slave flight, much as slave catchers and slave patrols did. Laws to prevent manumission by a master frequently required the posting of bonds to prevent those freed from becoming a financial burden on their communities. Later manumission laws often mandated the physical departure of those freed, creating emotional turmoil for the newly emancipated.