CADWorx Plant II tab: Dimensions > Tick Mark 
Gaskets, Etc. toolbar: Tick Mark
Command line: TICK
Shows which side of the dimension extension line the gasket is on.
This command is dependent upon the DIMSCALE being set properly. For example; if the gasket thickness was set to 1/8" and the scale of the drawing was set to full, the distance from the extension line to the tick mark would be 1/8". If the scale of the drawing was set to 3/4"=1'-0", the distance from the tick mark to the extension line would be 3/8". This insures that the tick mark is visible on a plotted drawing.
The initial prompt allows you to set the thickness, but does not appear again during the single drawing session. Changing the thickness is allowed in the next prompt.