Since some of the descriptions are very short, you probably should run topic more than once, trying partial words, synonyms, and related words as alternate strings.
Some discussion groups are available in more than one format.
It is not always possible to determine from the names or descriptions that two things contain the same material. The available index files that topic uses overlap to some extent, so its output may list some mailing lists more than once, with more or less differing descriptions. The different descriptions may even be helpful in some cases.