Nicene and Post-Nicene Fathers, Ser. II, Vol. XIV:
The Canons of the Councils of Ancyra, Gangra, Neocæsarea, Antioch and Laodicea, which Canons were Accepted and Received by the Ecumenical Synods.: Canon V

Canon V.

As many, however, as went up in mourning attire and sat down and ate, weeping throughout the whole entertainment, if they have fulfilled the three years as prostrators, let them be received without oblation; and if they did not eat, let them be prostrators two years, and in the third year let them communicate without oblation, so that in the fourth year they may be received into full communion.  But the bishops have the right, after considering the character of their conversion, either to deal with them more leniently, or to extend the time.  But, first of all, let their life before and since be thoroughly examined, and let the indulgence be determined accordingly.

Notes.

Ancient Epitome of Canon V.

Those who have gone up in mourning weeds, and have eaten with tears, shall be prostrators for three years; but if they have not eaten, then for two years.  And according to their former and after life, whether good or evil, they shall find the bishop gentle or severe.

Herbst and Routh have been followed by many in supposing that “oblation” (προσφορά) in this canon refers to the sacrament of the altar.  But this seems to be a mistake, as the word while often used to denote the whole act of the celebration of the Holy Eucharist, is not used to mean the receiving alone of that sacrament.

Suicer (Thesaurus s.v. προσφορά) translates “They may take part in divine worship, but not actively,” that is, “they may not mingle their offerings with those of the faithful.”

Hefele.

But as those who cannot present their offerings during the sacrifice are excluded from the communion, the complete meaning of the canon is:  “They may be present at divine service, but may neither offer nor communicate with the faithful.”