How do I blacklist guests?

Whilst there is no official blacklisting feature in Elina this scenario can be managed using our notes module. 
We recommend creating a note topic in Tasks -> Notes Administration for this purpose and then to create notes with the relevant information in the guest profile. 
Using the Notes List (Tasks -> View Notes) and the Topic filter you can then simply bring up a list of notes/guests that have been blacklisted including all relevant information inside of these notes.