metasploit – The output format of search in msfconsole

I see the following output from search in msfconsole.

msf6 > search CVE-2014-3566

Matching Modules

   #  Name                                Disclosure Date  Rank    Check  Description
   -  ----                                ---------------  ----    -----  -----------
   0  auxiliary/scanner/http/ssl_version  2014-10-14       normal  No     HTTP SSL/TLS Version Detection (POODLE scanner)

Interact with a module by name or index. For example info 0, use 0 or use auxiliary/scanner/http/ssl_version

But it is not clear what some of the columns mean. For example, what is Rank, what are its allowed values? What is Check, what are its allowed values? Thanks.