Author is usually the first to write on a subject, further than that its coauthor or comments

Forum shows latest commentator as author, maybe put them in a column called "latest"

Maybe 2 columns "author" "last post"

now the titled column "author" has below it

"author [abstract name {which can be different to login name} of last messager]"

either an overuse of author

or a transition towards having original author plus lastest comment