There is no real reason to go searching through back threads. Using the search feature at the top of the forum will allow you to search by author, subject or message. I have found this search feature to be very efficient and helpful. Thanks webmaster Rick.
A search for "Bluesky" reveals no posts by such an author, and the only time it appears in a message is in the above one. However this neither proves that it is the same person as Katerina or that it is not. Skeptical what environmental bulletin-boards are you refering to?