New form I-129 ggss2006-05-12 21:38:37

I am filling out the new form I-129 (Rev. 04/01/06). Some places are really confusing. But the most confusing one is on Part 5, item 3: "LCA Case Number", what is it? Should I fill in the three digit LCA Code or the "ETA Case Number" on the Labor Condition Application from Department of Labor? Thanks for your help.