Swing, the most likely one to be misused, means Ends and adjacent Centers Arm Turn 1/2, which doesn't make sense from facing dancers.

Slide means Ends and adjacent Centers exchange positions by sliding nose-to-nose.

Occasionally these calls are used from couple positions where the caller expects the dancers to Partner Trade instead of Swing or Slip, and to Half Sashay Trade instead of Slide or Slither. I don't like this usage unless the call is preceded by extra words such as 'Do Your Part' or 'Two-Faced'.