A log comprising a list of numbers called on a telephone, be it a landline, cell phone, or Internet-based (IP telephony, Voice over IP), usually recorded by a "D.N.R.," dialed number recorder. Technically, a DNR is the recording apparatus itself, but the term can denote one of a number of sets of data, e.g., intercepted text or instant messages, faxes, procured through a court-ordered electronic
communications intercept. I think this can also mean any evidence-level phone log or
conversation. A DNR is part of
communication collection equipment used by law enforcement, investigators, the government, and other entities.
This is probably one reason why gangsters uses burners or throwaway phones. Another is that law enforcement entities can remotely listen in and record conversations through remotely activated speaker/mic systems in the target's celly -- even with the phone turned off.