except when they're in square brackets:
```ruby
2.0.0p195 :001 > "abc" =~ /[.]/
 => nil 
2.0.0p195 :002 > "abc" =~ /[*]/
 => nil 
2.0.0p195 :003 > "abc.123" =~ /[.]/ 
 => 3
2.0.0p195 :004 > "abc*123" =~/[*]/
 => 3 
```
`/\.|F|\*/` and `/[.F*]/` are functionally identical.