A directed donor is a known or "private" donor. The directed donor may be a relative of the husband or an individual that you know.
Some sperm banks have "directed donor programs" that will assist you in the required testing and processing. The potential donor will need to have a semen analysis before proceeding because his sperm count and motility may not be satisfactory.
The FDA requires that all donors must under go the same infectious disease testing that regular donors must have.