Department of Homeland Security Management Directive System 3160: Attendance at Meetings and Conferences [open pdf - 38KB]
"This directive establishes Department of Homeland Security (DHS) policy regarding attendance at meetings and conferences. [...] This directive applies to all DHS organizational elements, all DHS employees and to employees of contractors who provide services at DHS expense. Until such time as the DHS Office of the Chief Human Capital Officer establishes permanent, Department-wide policy regarding attendance at meetings and conferences, all DHS organizational elements may continue in force their existing policies and procedures with respect to this matter."
Department of Homeland Security Management Directive System MD No. 3160
United States. Dept. of Homeland Security: http://www.dhs.gov/