Some statistical packages automatically indicate significantly differing letter. However, others like SPSS does not. Once the post hoc analysis is completed in SPSS, the out shows the pairwise comparisons between all treatments and then comes the task of summarizing and tabulating results. This task is quite simple when there are a few treatments to make comparisons, but becomes complicated and sometimes erroneous as the number treatments increases (e.g. 10 or more treatments). If there is a manual and systematic method of segregating significantly differing treatments with letters, the task of summarizing outcome would be less burdensome. This is in the absence of other packages. I would be grateful for your input.