Polyclad flatworm. This is a euphyllia menace and the Polyclad Flatworm lays its eggs along the body of the skeletal structure up to where the polyps extend out of the skeleton. The eggs can also be difficult to spot. More importantly, dipping will do absolutely nothing to Polyclad Flatworm eggs.
Before dipping the coral use a soft narrow bristle toothbrush and scrubbed the eggs off. After dipping the coral for five minutes place it in quarantine. 48 hours later examine the coral closely and scrub off any more eggs.
The best bet at eradication is to dip the affected coral 2-3 times over a week long period while also carefully brushing away any eggs that may be present. An R/O dip will also work with juvenile and adult Polyclad Flatworms, but manual extraction is necessary to remove the eggs.