Written Certification definition from the State of Maine:

” A document on tamper resistant paper signed by a medical provider that is valid for the term provided by the qualifying patients medical provider, expect that the term of a written certification may not exceed one year, and that states that in the medical providers’s professional opinion a patient is likely to receive therapeutic or palliative benefit from the medical use of marijuana to treat or alleviate the patients medical diagnosis or symptoms associated with the medical diagnosis.”