When you have a flatfile as a target for your ETL Powercenter prefixes the header of the file with a hash (#) character when you choose to have Powercenter generate the header from the target definition port names. Usually you do not want this hash to be present in your file. The easiest way to get rid of this is to add a custom property to your session configuration.
Navigate to the ‘Config Object’ tab and add the following property.
RemoveOutputHeaderHash=Yes
Click image for larger view