cuff

The man whom we had known as Douglas turned up his own coat and cuff to show a brown triangle within a circle exactly like that which we had seen upon the dead man.

“What else can be indicated by that right cuff so very shiny for five inches, and the left one with the smooth patch near the elbow where you rest it upon the desk?”

“That is of enormous importance,” said Holmes, making a note upon his shirt-cuff.

Holmes.” He scribbled the appointment on his shirt-cuff and hurried off in his strange, peering, absent-minded fashion.