This Global Detention Project (GDP) working paper attempts to map the web of international and regional instruments and mechanisms that together make up the “solid legal framework” relevant to the phenomenon of migration-related detention, which the Global Detention Project defines as the “deprivation of liberty of non-citizens because of their status.” Deprivation of liberty on these grounds typically takes the form of administrative detention—detention in the absence of a criminal charge—though there are increasing instances of states criminalizing irregular entry or presence. Migrant detainees can include asylum seekers and refugees, irregular immigrants, stateless persons, and victims of trafficking.