The inscription C V R M S V N on the Curmsun Disc is Old Norse written in the Latin alphabet or more precise a transliteration from Younger Futhark into 10th century Latin of the name Gormson (see also DR 55 section 1.1 and DR 295 section 1.1):
ᚴ ᚢ ᚱ ᛘ ᛋ ᚢ ᚾ
C V R M S V N
One of the earliest inscriptions of Old Norse written in the Latin alphabet is the word king on the so called Raven Penny (939-941) and Raven Banner Penny (early 940s). The word for king in Old Norse is Konungr and a transliteration from that word written in runes will result in the inscriptions of the Raven Pennies:
ᚴ ᚢ ᚾ ᚢ ᚾ ᚴ
C V N V N C
The Younger Futhark only contained of 16 characters but at the end of the 10th century and in the beginning of the 11th century, three dotted runes were added in order to represent the phonemes in a more exact manner. Rather than create new runes for the /e/, /ɡ/ and /y/ phonemes, dots were added to the i, k and u runes.
Around year 1000 and onwards an inscription of the Old Norse words Gormson and Konungr written in the Latin alphabet should have resulted in:
G V R M S V N instead of C V R M S V N and
C V N V N G instead of C V N V N C
due to the k-rune with a dot for the phoneme g.
One example that strenghtens this theory is the coin of Sihtric (Sigtrygg II Silkbeard Olafsson), the son of Olaf Sihtricson. Sihtric became king of Dublin in 989 and his coins bear the inscription SIHTRIC CVNVNG DYFL. DYFL is an abbreviation for Dyflin, Old Norse interpretation of the Irish place name but not a transliteration from Younger Futhark to Latin alphabet. DYFL could also be an abbreviation of the Latinized term DYFLINIENSIUM NORMANORUM (of the Norsemen of Dublin). The inscription CVNVNG suggests that a transliteration of the Old Norse word Konungr is made with the dot added to the k-rune to mark the soft guttural g.
The inscription on the Curmsun Disc reads CVRMSVN and not GVRMSVN. This indicates that the Curmsun Disc was made before the introduction of the dotted k-rune in the late 10th century.
The section above is based on a philogical article (link)