6.6 Avoiding Difficulty in Pronunciation [X.34.b(7)]

Another general restriction on the use of contractions is that they are not used if their use would cause difficulty in pronunciation, especially in uncommon or rarely used words. For example, the sign for ed is not used in Airedale, battledore, skedaddle, or predacious, nor should the sign for ing be used in lingerie or distingué. The er contraction is not used in diaeresis (di/aer/e/sis) because although aer constitutes a trigraph and a syllable, the use of the er contraction would make this unfamiliar word difficult to pronounce.