This is from the Transalpine Redemptorists via Eric Sammons' excellent Divine Light blog.
Apparently Pope Saint Pius X allowed communicatio in sacris (i.e. shared communion) with the Orthodox with the Russian Orthodox in certain cases:
Most Blessed Father!
Andrew Szeptycki, Metropolitan of Halycz, Metropolitan of Kiev and Administrator of all Russia at the foot of His Holiness most humbly asks that faculties may be conceded to himself and also to confessors in communion (capable of being communicated) for dispensing secular faithful from the law which forbids communicatio in sacris with the Orthodox as many times as they will judge it in conscience to be opportune.
Our Most Holy Father Pope Pius X deigned to sign with his own hand this document written by me with the words “May be tolerated”.My only worry is that the document isn’t the original and that it doesn’t bear an official protocol number.
I’m not doubting the document, I’m only saying that people may find the document dubious without the actual signature or protocol number.
ad Jesum per Mariam,