By default (GenBack=1, patmat=FALSE) the following 7 relationships are
distinguished:
S: Self (not included in Counts)
 
MP: Parent
 
O: Offspring (not included in Counts)
 
FS: Full sibling
 
HS: Half sibling
 
U: Unrelated, or otherwise related
 
X: Either or both individuals not occurring in both
     pedigrees
 
In the array and dataframe, 'MP' indicates that the second (column)
individual is the parent of the first (row) individual, and 'O' indicates the
reverse.
When GenBack=1, patmat=TRUE the categories are (S)-M-P-(O)-FS-MHS-PHS-
U-X.
When GenBack=2, patmat=TRUE, the following relationships are
distinguished:
S: Self (not included in Counts)
 
M: Mother
 
P: Father
 
O: Offspring (not included in Counts)
 
FS: Full sibling
 
MHS: Maternal half-sibling
 
PHS: Paternal half-sibling
 
MGM: Maternal grandmother
 
MGF: Maternal grandfather
 
PGM: Paternal grandmother
 
PGF: Paternal grandfather
 
GO: Grand-offspring (not included in Counts)
 
FA: Full avuncular; maternal or paternal aunt or uncle
 
HA: Half avuncular
 
FN: Full nephew/niece (not included in Counts)
 
HN: Half nephew/niece (not included in Counts)
 
FC1: Full first cousin
 
DFC1: Double full first cousin
 
U: Unrelated, or otherwise related
 
X: Either or both individuals not occurring in both pedigrees
 
Note that for avuncular and cousin relationships no distinction is made
between paternal versus maternal, as this may differ between the two
individuals and would generate a large number of sub-classes. When a pair is
related via multiple paths, the first-listed relationship is returned.
When GenBack=2, patmat=FALSE, MGM, MGF, PGM and PGF are combined
into GP, with the rest of the categories analogous to the above.