A lot of societies that I am a member of allow online voting for their AGMs (to elect members, approve minutes, etc). To vote in these all members are sent out a two part code - however the two codes are always sent together either in an email or a letter.
The way I see it the two parts of the code should be sent ideally over different channels (e.g. one part via email, one part via letter) or at least at different times (e.g. two emails sent on different days). I realise this would make things a bit more difficult for the voter (losing one of the codes, having to wait for second code before they vote), but what is the point of sending two codes together? Why not just issue a single code to be used?
The codes I receive are often of the format:
Code 1: 12345678 Code 2: abcd