The EQUALSLOPES and UNEQUALSLOPES options in the MODEL statement enable you to add or relax constraints on parameters in nominal response models and partial proportional odds models.
The INCLUDE=EQUALSLOPES specification in the MODEL statement facilitates model selection by enabling you to include all the equal slope effects in every model and perform the selection process on the unequal slope effects.
The START=EQUALSLOPES specification in the MODEL statement facilitates model selection by enabling you to begin the model selection process with all the equal slope effects in the model.