Anyone beginning to read inscriptions on Russian icons will soon realize that there are two languages one is likely to encounter — first, Church Slavic for main inscriptions, titles, scroll inscriptions (such as that pictured above) and “liturgical” texts; second, Russian, which is occasionally used for added details about when and by whom an icon was painted, and for what purpose it was painted (such as a commemoration of an event, a donation to a church, etc.). The primary and most prevalent language on icons is Church Slavic, which is closely related to Russian, but is different enough that modern Russians have some difficulty in understanding it.
The traditional Russian Orthodox Bible was printed in Church Slavic (Bible reading did not become popular in Russia until quite late, through the efforts of a Protestant Bible society, and even then it was only the New Testament that was generally read by Russian laypersons somehow lucky enough to be literate).
There are generally two kinds of inscriptions on Russian icons. The first is written in ordinary, quite legible Church Slavic Cyrillic letters (which in some cases vary from those used in modern Russian). The second, however, is quite different. It is a stylized calligraphic decorative form of Church Slavic writing using abbreviations, elongated and stylized letter forms, inserted smaller letters, and even tiny letters written as superscriptions (written above the larger letters, in which they are mentally to be inserted). This form of decorative writing is extremely common on Russian icons, particularly in the titles of icons. In English we call it a “condensed” inscription for convenience, because it does look like it has all been squeezed and condensed into an abbreviated form, but in Russian it is called Vyaz (Вязь).
Vyaz incriptions were used on icons because they have a decorative, formal appearance. They were also used on other objects, such as in book headings, or engraved on copper, brass or silver utensils. Such ornate inscriptions are often a complete mystery to the beginning student of icons, but the key to understanding them is this: First, one must have a basic and simple vocabulary of common Church Slavic terms, words that are very repetitive in icons, such as “Holy” “God” “Apostle” “Martyr” etc. etc. That is not at all difficult to achieve. Second, one must have a great deal of patience, because in Vyaz there are three obstacles:
The first, already mentioned, is learning a basic, elementary icon vocabulary;
The second is distinguishing and recognizing the ornate forms of the letters used in the inscription;
The third is learning where the words separate.
As for the second of these obstacles, it exists because Vyaz letters vary widely in their ornateness and appearance, so one must learn to recognize the basic form of the letter from its ornate form, and these ornate forms vary widely in their complexity. The third obstacle — learning to separate each individual word — is necessary because Vyaz letters are not only often joined to one another but also are run together from one word to another without intervening space or punctuation. This is similar to the problem those reading an ancient uncial manuscript of the Greek New Testament face — one has to determine where a word or a sentence ends and another begins in order to determine what it means. You can easily see why these can be obstacles from this old book example of Vyaz: 
It is fairly typical of the kind of thing one faces in reading Vyaz inscriptions on icons. We can “expand” the condensed inscription by reading it letter by letter from left to right, very carefully and patiently. 
The first word in the inscription consists of two letters — a Church Slavic “O” (which looks like an odd “W”), and in the middle space of the “O” is a “T” that looks much the same as our “T” in English. Together these from the word “OT,” meaning “From” or “OF.” The second word is a proper name, “MARK,” which appears here in the form “MARKA.” 
The first “A” is above and connected to the right upright bar of the “M.” Then comes a full-length “R” (which looks like “P” to an English speaker), followed by a “K” and then an upright “A,” which in ornate form looks like a long “I” with a little diamond attached to its left side. So that is MARKA –“MARK.” Next comes the abbreviated word “SVYATOE” — A form of “SVYATUIY,” meaning “HOLY”: 
We see the “S” that looks like a Roman “C” on the left, the “T” in the upper middle, the “O” in reduced size at the middle bottom, and the “E” on the right side. The other letters are omitted, as shown by the curved line above the “T,” and must be supplied by the reader. The next and final word is longer, but it is useful to know: 
That is the word “BLAGOVYESTVOVANIE,” which means literally “Good News” in Slavic, and it is a word used to mean “GOSPEL.” The curved line above the second and third letters indicates abbreviation by omission of a letter, in this case the absence of the letter “A,” which the reader must supply. That is why one must know the basic vocabulary in order to recognize and distinguish individual words. 
All together, this Vyaz inscription reads: “OT MARKA SVYATOE BLAGOVYESTVOVANIE” That means simply “[THE] From/Of Mark Holy Gospel,” which we would translate into English as “THE HOLY GOSPEL OF MARK.” The same principles used in this little example apply to the countless Vyaz titles one finds written on icons, so it is very important to take the amount of time necessary to form a basic vocabulary of Church Slavic (don’t think you have to learn the entire Church Slavic language — you do not!) and to learn to recognize the ornate calligraphic forms of letters used in writing Vyaz. These are the keys that unlock those attractive but often mysterious (though generally rather simple) titles that identify an icon type.
This must all seem very complex and exotic to the beginning student of Russian icons, but I assure you that it is much simpler than it looks on first examination. The reason, again, is that Russian icon inscriptions in Church Slavic are extremely repetitive, so one encounters the same common words and phrases over and over again. That is why a little study gives great rewards in the ability to read and translate icon inscriptions.
You may wish to know what the scroll at the top of this posting says. It is taken from Ezekiel 33:11:
Не хощу смерти грешникомъ но во еже обрати[тися нечестивому от пути своего и живу быти ему]
“I do not desire the death of the sinner , but that he should turn from his path and live.”
ICONS AND THEIR INTERPRETATION 