Though not specifically for veterans, the Schedule A authority for people with certain disabilities, 5 CFR 213.3102(u), is an excepted authority that agencies can use to appoint eligible veterans who have a psychological, intellectual, or severe physical disability.
Agencies can use this authority, at their discretion, to appoint an eligible veteran at any grade level and for any job (time-limited or permanent) for which they qualify. After 2 years of satisfactory service, the agency may convert the veteran, without competition, to the competitive service.
Additional information on the use of the Schedule A appointing authority for persons with certain disabilities can be found on the OPM website.