GLM, GLZ, PLS, and MANOVA Syntax - Keyword Param

PARAM [=] { SIGMA }
  { OVERP };

Example. PARAM = OVERP;

Optional keyword; specify either the sigma-restricted model (SIGMA), or the overparameterized model (OVERP); SIGMA is the default parameterization, except for nested designs or mixed-model ANOVA and ANCOVA designs. See The sigma-restricted vs. overparameterized model for additional details.

Applies to
GLM, GLZ, PLS, and ANOVA/MANOVA