Thanks, I'll give that a shot.

1. The instructions are unclear. The instructions state: If there are numbers or special characters included in the string, they should be returned as they are. Only letters from the latin/english alphabet should be shifted, like in the original Rot13 "implementation".

First, it should explicity say what should be returned as they are...do you mean the string? or the character.

2. In some of the test cases how do 2 different non-alphanumeric characers with rot13 applied equal the same character? As in..
   'nopqrstuvwxy`abcdefghijklm' should equal 'nopqrstuvwxyzabcdefghijklm'
   'nopqrstuvwxyz{bcdefghijklm' should equal 'nopqrstuvwxyzabcdefghijklm'

'@Y3SEVEEEK37VH68' should equal 'ZY3SEVEEEK37VH68'
'@L3FRIRRRX37IU68' should equal 'ML3FRIRRRX37IU68'