Thus, the language included distinct sounds and minimal pairs which weren't separate in writing. Also, since the writing custom avoided having the same rune twice in consecutive order, the spoken distinction between long and short vowels weren't retained in writing, either. The only real reason for using the same rune consecutively, would be when it represented different sounds following each other, such as carving kunuur for the name Gunvor.
There is a transitional phase from ca. 650 to 800 showing mixed use of Elder and Younger Futhark letters, for example the Björketorp (ca. 650), Stentoften (ca. 650), Snoldelev and Rök (ca. 800) stones.
The Younger Futhark became known in Europe as the "alphabet of the Norsemen", and was studied in the interest of trade and diplomatic contacts, referred to as Abecedarium Nordmannicum in Frankish Fulda (possibly by Walahfrid Strabo) and ogam lochlannach "Ogham of the Scandinavians" in the Book of Ballymote.
The Younger Futhark is divided into long-branch (Danish) and short-twig (Swedish and Norwegian) runes. The difference between the two versions has been a matter of controversy. A general opinion is that the difference was functional, i.e. the long-branch runes were used for documentation on stone, whereas the short-branch runes were in everyday use for private or official messages on wood. In addition the Hälsinge Runes (staveless runes, ca. 900–1200), Middle Age runes (ca. 1100–1500) and the Latinised Dalecarlian futhark (ca. 1500–1910) were developed out of the Younger futhark.
The long-branch runes are the following signs:
Hälsinge runes are so named because in modern times they were first noticed in the Hälsingland region of Sweden. Later other runic inscriptions with the same runes were found in other parts of Sweden. They were used between the 10th and 12th centuries. The runes seem to be a simplification of the Swedish-Norwegian runes and lack vertical strokes, hence the name 'staveless.' They cover the same set of staves as the other Younger Futhark alphabets. This variant has no assigned Unicode range (as of Unicode 4.0).
In the Middle Ages, the Younger Futhark in Scandinavia was expanded, so that it once more contained one sign for each phoneme of the old Norse language. Dotted variants of voiceless signs were introduced to denote the corresponding voiced consonants, or vice versa, voiceless variants of voiced consonants, and several new runes also appeared for vowel sounds. Inscriptions in medieval Scandinavian runes show a large number of variant rune-forms, and some letters, such as s, c and z, were often used interchangeably (Jacobsen & Moltke, 1941–42, p. VII; Werner, 2004, p. 20).
Medieval runes were in use until the 15th century. Of the total number of Norwegian runic inscriptions preserved today, most are medieval runes. Notably, more than 600 inscriptions using these runes have been discovered in Bergen since the 1950s, mostly on wooden sticks (the so-called Bryggen inscriptions). This indicates that runes were in common use side by side with the Latin alphabet for several centuries. Indeed some of the medieval runic inscriptions are actually in Latin language.