5 C.F.R. § 550.1505
Order of precedence.
If the authorized agency official determines the agency will furnish a flag, it must be issued to one beneficiary pursuant to the following order of precedence—
(a) The widow or widower;
(b) If none, to a child (including step, foster, or adopted child), according to age ( i.e. , oldest to youngest);
(c) If none, to a parent (including step, foster, or adoptive parent);
(d) If none, to a sibling (including step, half, or adopted sibling), according to age; ( i.e. , oldest to youngest);
If none, to any individual related by blood or close family affiliation.