What is the test for an administrative officer to make a rule or regulation that alters or enlargens the terms of a legislative enactment?

The court, in Pitts v. Perluss, 58 Cal.2d 824, 832, 27 Cal.Rptr. 19, 24, 377 P.2d 83, 88 stated that the court should not 'superimpose its own policy judgment upon the agency in the absence of its arbitrary and capricious decision.' People v. Mangiagli, 97 Cal.App.2d Supp. 935, 943, 218 P.2d 1025, 1030, states that where a statute has a doubtful meaning or is ambiguous, a regulation is appropriate, but "An administrative officer may not make a rule or regulation that alters or enlarges the terms of a legislative enactment."