I am using Mapserver v5.6 and used MapFile with 2 layers. One layer to show polygon and other to show label at ST_PointOnSurface of the same polygon... There are another way to show unique-label at POSITION CC of the polygon?
I tested REPEATDISTANCE 9999 but no effect.
Even Mapserver v6 documentation have no instruction about "no-repeat" options.
The polygon-layer was tested (with no effect) with this mapfile fragment for label
LABEL
ALIGN center
FONT "ubuntu"
TYPE TRUETYPE
SIZE 15
POSITION CC
COLOR 255 0 0
REPEATDISTANCE 9999
OUTLINECOLOR 50 200 60
END #label