Overshoots and Undershoots happen when your drawn line doesn’t connect exactly with the neighboring line it should intersect with. Mostly, the error only becomes visible with a large zoom level.
In OCAD, there is a function that removes Over- and Undershoots of selected lines. If you want to prevent Over- and Undershoots, enable the Snapping function.
For an animation and more information, please see our Wiki.
The International Orienteering Federation IOF has updated the recommendations for Printing and Color Definitions according to modern practices.
OCAD implemented the new color specification in the latest OCAD 2018 Service Update. Download this Service Update from the OCAD Help menu.
You can read the Appendix to ISOM 2017, which explains the background of the update and the different printing techniques, here: ISOM 2017 Appendix 1 – CMYK Printing and Colour Definitions.