CPSGT is a trademarked designation. Only sleep techs who have successfully passed the CPSGT Exam – and who have adhered to continuing education policies, may use CPSGT after their name.
The only correct way to display the credential is to follow your name with CPSGT in all caps:
Jane Doe, CPSGT
Jane Doe, C.Psg T
Jane Doe, CPsgT
Jane Doe, C.P.S.G.T.