St. Nicholas' Cross
also known as St. Olga's Cross
Many associate St. Nicholas with Santa Claus, rather than Saint Nicholas himself or his cross.
Even so, he is one of the most popular saints, especially for Eastern Catholics and the Orthodox. Due to his charity and concern for the welfare of children, the Archbishop Nicholas (280-342 A.D.) of the Mediterranean port of Myra (Turkiye) became Saint Nicholas and is the patron of children and travellers.
This Eastern background is the reason the St. Nicholas Cross is usually an Eastern Orthodox style superimposed on a Budded Cross and often embellished with the acronym IC XC NIKA.
For a little more on Santa Claus, see Pagan background of Christmas. See also the Christmas Natal Cross.
Greek abbreviations, common among Eastern Christians, where:
Ic are iota (Ι) and sigma (ς), the first and last letters of Jesus (Ιησους),
Xc are chi (Χ) and sigma (ς), the first and last letters of Christ (Χριστος),
and Nika (Νικα) means to be victorious or to conquer.
The interpretation is that Jesus Christ was victorious over death (Rom. 6:4) and through Him we can all conquer death Col. 2:12
See also ICXC Cross and the St. Nicholas Anchor Cross