Hi Graham,
For Pleco 3.2, it should work with special reserved Unicode characters. See this post:
Multiple new lines in user defined flashcards
Perhaps this the flashcard exchange thread but hope to reach a larger audience here. Is there a way to introduce new lines in user generated definitions so that difference "meanings" can be numbered and start on new lines (i.e. formatted line the cards generated from dictionary entries)?plecoforums.com