In the breast stroke breath is inhaled during the arm pull. The head is raised sufficiently high to life the chin above the water at the exact moment the arms open for the outward and backward pull. Air must be taken into the lungs through the open mouth, never through the nostrils. If air is drawn through the nose there is a decided risk of swallowing any water which may happen to be lying in the nasal passages, thus causing choking. The intake of air through the mouth should be an easy, slow movement performed after each stroke.
Nothing is left to chance as can be seen by the example wording from the reverse of a card.
That is generally the easy bit the other cards rather resemble one of the instructions you get with your video machine. This is tricky stuff now. We have all seen it done but that first time you are told you breathe out with your face in the water all hell breaks loose. Mind you breaking every stroke and forcibly expelling air sounds like a classic ingredients for a bit of hyper ventilation. Card 27 tells you the isolation of limb movement is a vital ingredient to a successful swimming action.