- Known crawler will be ticked for user agents that are known to be spiders, bots or crawlers. The lack of a tick doesn't prove that it is a bot, as there are many obscure bots which haven't yet been classified as such. And, of course, it's perfectly possible for a bot to fake the user agent of a normal browser.
- Often banned is ticked for any known crawlers or file downloaders that are also commonly banned by server administrators. This may be for many reasons, including malicious behaviour or excess bandwith and resource use. You should not rely on this as an indicator of the malicious nature or otherwise of the bot. Truly malicious bots use fake user agents, anyway.