http://www.unco.edu/center/es/ocdp/ocdp_program.htm In this case, it looks like DL means that it is offered at an off campus location (or three) as a night/weekend program.
My daughter is completing her MA in Counseling through UNC at the Colorado Springs extended campus. Tuition has averaged about $250 a credit hour. Although she has done well she is very unhappy with the program administration. Most instructors are professors from Greeley and she has had to contact them numerous times to get simple questions answered. Her advisor knows little about what is going on and gives her advice that conflicts with the graduate student handbook. UNC has had these programs for years you would think they would have the problems ironed out by now. I have told her to tough it out since she is near the end. She just wants to graduate and the bad experience has made her rethink getting into the counseling field. Other UNC programs may be better run.