It is often omitted in printed works because the sign is missing on modern keyboards. The acute and grave accents are occasionally used in poetry and lyrics: the acute to indicate stress overtly where it might be ambiguous (rébel vs. rebél) or nonstandard for metrical reasons (caléndar); the grave to indicate that an ordinarily silent or elided syllable is pronounced (warnèd, parlìament). In historical versions of English The Old English Latin alphabet began to replace the Runic alphabet in the 8th century, due to the influence of Celtic Christian missionaries to the Anglo-Saxon kingdoms. The orthography of Old English – which was entirely handwritten in its own time – was not well standardized, though it did not use all the Latin letters, and included several letters not present in the modern alphabet. When reprinted in modern times, an overdot is occasionally used with two Latin letters to differentiate sounds for the reader: ċ is used for a voiceless palato-alveolar affricate /t͡ʃ/ ġ for a palatal approximant /j/ (probably a voiced palatal fricative /ʝ/ in the earliest texts) Some modern printings also apply diacritics to vowels following the rules of Old Norse normalized spelling developed in the 19th century. In the Late Middle English period, the shape of the English letter þ (thorn), which was derived from the Runic alphabet, evolved in some handwritten and blackletter texts to resemble the Latin letter y. The þ shape survived into the era of printing presses only as far as the press of William Caxton. In later publications, thorn was represented by "y", or by ẏ to distinguish thorn from y. By the end of the Early Modern English period, thorn had been completely replaced in contemporary usage by the digraph "th" (reviving a practice from early Old English), and the overdot was no longer needed outside of printings of very old texts. The overdot is missing from the only surviving usage of a Y-shaped thorn, in the archaic stock phrase ye olde (from "þe olde", pronounced "the old", but "ye olde" is often misanalyzed and pronounced with the modern "y" sound). Words imported from other languages Loanwords have enter the English language from another language by a process of naturalisation, or specifically anglicisation, which is carried out mostly unconsciously (a similar process occurs in all other languages). During this process there is a tendency for accents and other diacritics that were present in