The CESSDA ERIC (Research Infrastructure for the Social Sciences) has published two policy documents in relation to PIDs, see:
Hausstein, Brigitte, Kerrin Borschewski, Birger Jerlehag, and René van Horik. 2017. CESSDA ERIC Persistent Identifier Policy (Principles). CESSDA ERIC Knowledge Platform. https://doi.org/10.18448/16.0040
Hausstein, Brigitte, Kerrin Borschewski, René van Horik, and Birger Jerlehag. 2017_2. CESSDA ERIC Persistent Identifier Policy (Best Practice Guidelines). CESSDA ERIC Knowledge Platform. https://doi.org/10.18448/16.0041