From USAJOBS Help
Interagency Career Transition Assistance Plan (ICTAP) gives an eligible, well-qualified employee selection priority over almost any other applicant from outside the agency. Under ICTAP, employees must apply for positions in the local commuting area and include proof that they were displaced. For example, a Department of Defense employee with a Reduction in Force (RIF) separation notice could apply for a competitive service vacancy in the local commuting area at the Department of Education. In most cases, Education must select this well-qualified person for the position before choosing another applicant from outside the agency.