I am always in two minds whether or not to include apostrophes if applicable to crossword answers, especially when the square in question is only relevant to one answer. Can anybody help me out on this one, or does it really not matter either way?
When the square in question serves two words the answer is obvious - omit any accent or apostrophes. So this custom must apply equally in other, specific squares.
Whether an apostrophe is needed or not depend on the word pattern given in the clue. These days apostrophes are normally omitted - too much of a giveaway?