Given a category and a set of five words, find the word from the set that does not belong (i.e. is the least relevant) with the other words in the category. Words are separated by commas.

Category: moral characteristic 
Words: milky, fair, ok, loyal, unprejudiced
milky

Category: secretary duty 
Words: file, software, schedule, support, order office supplies
software

Category: construction 
Words: sandpiper, derrick, tackle, crane, excavator

sandpiper