The inscription on the runestone of Harald was made as a message regarding the king´s reign instead of earlier runic inscriptions which were made for describing and maintaining different issues. Furthermore, the runic inscription of Harald was made horizontal for the first time which Preben Meulengracht Sørensen consider as the first known sign of an upcoming Latin written culture in the Nordic countries (link).
Meulengracht Sørensen´s theory makes perfect sense if we regard a horizontal text with a message on the runestone of Harald followed by the Curmsun Disc which also had a message but now in Latin with a partial use of runes if we count the transliteration from Gørmson written in runes to CVRMSVN.
Runestone of Gorm – Vertical describing runic inscription
“King Gormr made this monument in memory of Thyrvé, his wife, Denmark’s adornment.”
Runestone of Harald – Horizontal proclaiming runic inscription
”[…..] Haraldr who won for himself all of Denmark and Norway and made the Danes Christian.”
Curmsun Disc – Horizontal proclaiming Latin inscription
”Harald Cvrmsvn, king of Danes, Scania, Jumne, City of Oldenburg”