Does anyone know about this decree of excommunication that Pius XII issued?  

I've done a search and can't come up with anything.  

http://geocities.ws/caleb1x/docuмents/communism.html

In case the link does not work...........................

[EXCOMMUNICATION OF COMMUNISTS]
DECREE OF THE HOLY OFFICE
FORMULATED BY PIUS XII
JULY 1, 1949


This Sacred Supreme Congregation has been asked:

    1. whether it is lawful to join Communist Parties or to favour them;

    2. whether it is lawful to publish, disseminate, or read books, periodicals, newspapers or leaflets which support the teaching or action of Communists, or to write in them;

    3. whether the faithful who knowingly and freely perform the acts specified in questions 1 and 2 may be admitted to the Sacraments;

    4. whether the faithful who profess the materialistic and anti-Christian doctrine of the Communists, and particularly those who defend or propagate this doctrine, contract ipso facto excommunication specially reserved to the Apostolic See as apostates from the Catholic faith.

The Most Eminent and Most Reverend Fathers entrusted with the supervision of matters concerning the safeguarding of Faith and morals, having previously heard the opinion of the Reverend Lords Consultors, decreed in the plenary session held on Tuesday (instead of Wednesday), June 28, 1949, that the answers should be as follows:

    To 1. in the negative: because Communism is materialistic and anti-Christian; and the leaders of the Communists, although they sometimes profess in words that they do not oppose religion, do in fact show themselves, both in their teaching and in their actions, to be the enemies of God, of the true religion and of the Church of Christ;

    to 2. in the negative: they are prohibited ipso iure (cf. Can. 1399 of the Codex Iuris Canonici);

    to 3. in the negative, in accordance with the ordinary principles concerning the refusal of the Sacraments to those who are not disposed;

    to 4. in the affirmative.

And the following Thursday, on the 30th day of the same month and year, Our Most Holy Lord Pius XII, Pope by the Divine Providence, in the ordinary audience, granted to the Most Eminent and Most Reverend Assessor of the Sacred Office, approved of the decision of the Most Eminent Fathers which had been reported to Him, and ordered the same to be promulgated officially in the Acta Apostolicae Sedis.

    Given at Rome, on July 1st, 1949.

    (Signed) Petrus Vigorita,

    Notary of the Sacred Supreme Congregation
    of the Holy Oflice.





For the heck of it, here is a  newspaper article from 1949 about it.

Not to make light of this important issue, but much like no current or future hockey player is permitted to wear #99 in the NHL, neither is another pope permitted to use the name of Peter....Anyways, I'm expecting a disruption of some sort at the conclave, which would essentially put Card Bertone in charge of church affairs in the interim. Of course, when a pope dies, or in this case abdicates, the curia ceases to exist in the sense that it may not make any decrees, make decisions of importance. Their only duties are to attend to day to day church affairs. Much like when a parliamentary government falls.,,,,,this is my take on things at least.