Error in vmstat documentation (man page)
The man page for vmstat(8) says this about the --unit option:
"Note this does not change the swap (si/so) or block (bi/bo) fields."
However, inspection of vmstat.c and experimentation with the binary itself both confirm that the units of the swap (si/so) fields are controlled by the --unit option. The documentation should be modified to read (with some optional extra helpful guidance added):
"Note this does not change the block (bi/bo) fields, which are always measured in blocks."
Also, as another more debatable suggestion; it'd be good to add brief notes to the "FIELD DESCRIPTION FOR VM MODE" section (even just "(see --unit option)" would instill much more confidence.)