UltraEdit, UltraCompare, UEStudio forums

I have 2 list of object identifiers. One file has about 6 millions rows and the other one has about 20 thousands rows. I want to find from smaller list file all lines which are not present in large data file. An example for the lines in both files: 09000071800d230d 09000071800d230e 09000071800d230f ...