Questione giuridica chiave
Whether the fax-filed federal appeal met the formal filing requirements.
Decisione estratta
No. A federal appeal must be filed by hand delivery, post, or electronically with qualified signature; a fax submission is invalid.
Motivazione estratta
The filing did not comply with Art. 48(1) and Art. 42(4) BGG. Despite a prior notice inviting a valid filing, no proper appeal was submitted.