Tyr is the twelfth of the sixteen Younger Futhark runes, descending from Tiwaz, the Elder Futhark's own seventeenth rune, and shares with the Old English Tir, discussed at length elsewhere in this survey, the distinction of preserving an independently attested Germanic god's own name across every runic tradition this survey covers, Elder Futhark, futhorc and Younger Futhark alike, the clearest single thread of continuity running through all three systems. Barnes' handbook treats Tiwaz and its descendants as the strongest evidence available that at least some runic names carried genuine, stable mythological content across centuries and across the splits between traditions, in contrast to the considerable drift visible in runes such as Ur or Kaun.
Tyr's sound value t in the Younger Futhark absorbed, as with several of the row's other consonants, both the voiced d and unvoiced t sounds of spoken Old Norse, one rune covering a phonetic pair the language itself still distinguished, the same kind of deliberate economy Kaun's own account of the reduction described for the k and g sounds. Barnes treats Tyr's stability across every runic tradition as good evidence that at least a handful of divine names were considered too significant, or too well known, for any tradition's users to reinterpret or quietly set aside the way Ansuz's own name was handled in the Old English futhorc.