There are no restrictions for refs at airfields at wiki. XWPR isn't a local reference (local_ref). It's a national (& international between several countries like Russia, Belarus, Armenia, Qazaqstan etc.) reference. Please, don't change the official refs (by Federal Air Transport Service of Russia at «Руководство по авиационной электросвязи» 01.09.1999 & at «Сборник четырехбуквенных указателей (индексов) местоположения аэродромов, полигонов и посадочных площадок») from "ref" to "local_ref" or ref:aopa:*.