Inscribing the name of the icon is literally one of the most important steps in completing the process. Generally, the icon name or subject is written in the language of the people who will be using it.
But let’s say you would like to stay true to the genre and time period of the prototype and name your icon in Church Slavonic or Greek.
Below is a link to a lovely reference of common identifiers in iconography, translated to English and also written in Church Slavonic, Greek, listed with their respective centuries. See the two examples below of the name John:
John – 15th Century Russian
John – 16th Century Greek