Re: Trim and Clean .. how do you know when to?

Hi PBInonpro - using both is recommended if you are importing Excel files.  Please refer to the Power Query guidance to see the difference between removing blank spaces at beginning and end (trim) and removing special characters (clean).  
Text.Clean - PowerQuery M | Microsoft Learn
Text.Trim - PowerQuery M | Microsoft Learn

 

Note this may not remove all special characters like #?|.