The article is another voice in the discussion on the possibility of using anonymous letters in a civil trial. In particular, the author indicates arguments allowing for the classification of such evidence as a document within the meaning of procedural regulations (the Code of Civil Procedure). She also presents examples of anonymous letters that are already used in court proceedings. The article also highlights the issue of anonymous electronic documents. The problems related to the identification of issuers (authors) of documents in the lack of a signature were also discussed. The author points to the need to separate the anonym from the feature of immorality.