So we have the comparison tag, with 38 questions which does have a few highly voted posts, but overall is spread out over a broad range of topics, ranging from comparing DVDs to text files, to Ubuntu versions themselves. There's no wiki nor synonyms.
Meanwhile, we have a very specific tag for diff utility, which achieves exactly that purpose - comparing the data. If you excuse the pun, should we compare the cons and pros of getting rid of the former, overly broad tag ? Is it easier to make it a synonym of diff ?