For those who may wonder about the antimins/antimension:
This is the altar cloth which gives a priest the authority to conduct the Divine Liturgy. The antimins contains a relic of a saint sewn into it, and the cloth is signed by the ruling bishop, thus bestowing episcopal authority (imprimatur) on the right of that priest to conduct the Eucharist on the bishop's behalf, as it were.
The word for this altar cloth is derived from the Greek anti- (in place of), and the Latin mensa (table). From the earliest Christian period, liturgies were served on the graves or relics of martyrs and saints; this led to the practice of ensuring a holy relic was embedded into the altar of every consecrated Orthodox church. In the absence of a consecrated altar, such as a church not yet consecrated (the parish church in which I was baptised had to wait ten years before it was formally consecrated), or if a liturgy is to be held on board ship, in an outdoor space, in a hotel, or anywhere outside a consecrated church, the use of the antimins allows the proper and "valid" (I apologise for using this word) serving of the Divine Liturgy. The Liturgy held to commemorate the founding of a monastery near where I live was conducted using an antimension placed on a tree stump in the middle of a field, with icons of Christ and the Mother of God hung in forks of trees.
In short: Where there be the antimins, there be the Eucharist.