Veterans' Preference for Promotion; Requires state & political subdivisions to give veterans' preference in employment promotion; authorizes waiver of postsecondary educational requirements; requires DVA to adopt rules to ensure veterans' preference in promotion; requires numerically based selection process to be used to determine qualifications for promotion; requires preference in promotion in positions for which numerically based selection process is not used; provides for investigation & administrative hearing of complaint regarding veterans' promotion preference; provides that military retirement on basis of longevity does not disqualify person from veterans' promotion preference.