Hosts file name extension (or Non Extension)

[ksiemb]

The Hosts file Name in \windows\system32\drivers\etc shows

Name Type
Hosts File
Hosts.bak BAK File
Hosts.ics ICS File


Any explanation as to why the 1st entry's name is Hosts without the ext and not Hosts.fil seeing that the Type is File ?
Or is "File" not a valid extension ?

 

[Guest]

http://en.wikipedia.org/wiki/Hosts_file