Handbook of ROCOR Liturgical Practice:

When, and how, should the deacon tap the diskos at the priest’s exclamation: ‘singing the triumphant hymn …’?

As the Priest proclaims the words ‘singing the triumphant hymn…’, the Deacon should lightly tap the east side of the diskos with the asterisk (star); then the west side at the word ‘shouting’; the north side at ‘crying aloud’; and the south side at ‘saying’.

In each instance, a single tap is made of the associated foot of the asterisk with the edge of the diskos. This is done lightly and carefully, so as not to disturb the diskos.

When multiple Deacons concelebrate, this is performed by the second Deacon (who is standing to the Priest’s left). If a single Deacon serves, during the Priest’s mystical prayer prior to this moment, he crosses behind the Holy Table and takes up his place on the north side (or he may enter through the north door prior to this, so as to be in place there). Just before taking up the diskos, he faces east and crosses himself, turns and bows to the Bishop, then takes up the diskos in his right hand, in which he also holds his orar.

At the conclusion of the refrain, the Deacon himself kisses the asterisk and then folds it, placing it atop the folder aer which has already been placed on the north side of the Holy Table, to the east of the Cross with the spear and spoon (note, the folded asterisk is not placed centrally over the antimins, as is practiced in some other places).