This presentation will introduce the evolution of (P)ID implementation in the Materials Data Repository (MDR) and related services. MDR is a part of the Materials Data Platform "DICE" developed and operated by National Institute for Materials Science (NIMS). It has experienced several changes in its implementation of identifiers due to difficulties in applying and managing identifiers to research datasets in materials science – including specimens, instruments and chemical compositions – and changing requirements for the service. This presentation will include our example of implementing (P)ID, especially the details of the changes in the requirements and implementations in our data platform.