Close front rounded vowel

From Wikipedia, the free encyclopedia
Close front rounded vowel
IPA number 309
Entity (decimal) y
Unicode (hex) U+0079
Kirshenbaum y
Braille ⠽ (braille pattern dots-13456)

The close front rounded vowel, or high front rounded vowel,[1] is a type of vowel sound, used in some spoken languages. Acoustically it is a close front-central rounded vowel.[2] The symbol in the International Phonetic Alphabet that represents this sound is ⟨y⟩, and the equivalent X-SAMPA symbol is y. Across many languages, it is most commonly represented orthographically as ⟨ü⟩ (in German, Turkish and Basque) or ⟨y⟩, but also as ⟨u⟩ (in French and a few other Romance languages and also in Dutch and the Kernewek Kemmyn standard of Cornish); ⟨iu⟩/⟨yu⟩ (in the romanization of various Asian languages); ⟨ű⟩ (in Hungarian for the long duration version; the short version is the ⟨ü⟩ found in other European alphabets); or ⟨уь⟩ (in Cyrillic-based writing systems such as that for Chechen)

Short /y/ and long /yː/ occurred in pre-Modern Greek. In the Attic and Ionic dialects of Ancient Greek, front [y yː] developed by fronting from back /u uː/ around the 6th to 7th century BC. A little later, the diphthong /yi/ when not before another vowel monophthongized and merged with long /yː/. In Koine Greek, the diphthong /oi/ changed to [yː], likely through the intermediate stages [øi] and [øː]. Through vowel shortening in Koine Greek, long /yː/ merged with short /y/. Later, /y/ unrounded to [i], yielding the pronunciation of Modern Greek. For more information, see the articles on Ancient Greek and Koine Greek phonology.

The close front rounded vowel is the vocalic equivalent of the labialized palatal approximant [ɥ]. The two are almost identical featurally. [y] alternates with [ɥ] in certain languages, such as French, and in the diphthongs of some languages, ⟨⟩ with the non-syllabic diacritic and ⟨ɥ⟩ are used in different transcription systems to represent the same sound.

In most languages, this rounded vowel is pronounced with compressed lips ('exolabial'). However, in a few cases the lips are protruded ('endolabial').

Close front compressed vowel

The close front compressed vowel is typically transcribed in IPA simply as ⟨y⟩, and that is the convention used in this article. There is no dedicated diacritic for compression in the IPA. However, the compression of the lips can be shown with the letter ⟨β̞⟩ as ⟨i͡β̞⟩ (simultaneous [i] and labial compression) or ⟨iᵝ⟩ ([i] modified with labial compression). The spread-lip diacritic ⟨  ͍ ⟩ may also be used with a rounded vowel letter ⟨⟩ as an ad hoc symbol, though technically 'spread' means unrounded.


IPA: Vowels
Front Near-front Central Near-back Back

Paired vowels are: unrounded • rounded

  • Its vowel height is close, also known as high, which means the tongue is positioned as close as possible to the roof of the mouth without creating a constriction that would be classified as a consonant.
  • Its vowel backness is front, which means the tongue is positioned as far forward as possible in the mouth without creating a constriction that would be classified as a consonant. Note that rounded front vowels are often centralized, which means that often they are in fact near-front.
  • Its roundedness is compressed, which means that the margins of the lips are tense and drawn together in such a way that the inner surfaces are not exposed.


Note: Because front rounded vowels are assumed to have compression, and few descriptions cover the distinction, some of the following may actually have protrusion.

Language Word IPA Meaning Notes
Albanian Standard ylber [ylbɛɾ] 'rainbow' See Albanian phonology
Afrikaans Standard[3] u [y] 'you' (formal) See Afrikaans phonology
Azerbaijani[4] güllə [ɟy̠lˈla] 'bullet' Near-front.[4]
Bavarian Amstetten dialect[5] [example needed] Near-front.[5]
Breton[6] brud [bʁyːt̪] 'noise'
Catalan Northern[7] but [byt̪] 'aim' Found in Occitan and French loanwords. See Catalan phonology
Chinese Mandarin[8][9] / nǚ About this sound [ny̠˩˧] 'woman' Near-front.[10][11][12] See Standard Chinese phonology and Cantonese phonology
Cantonese[13] / s About this sound [sy̠˥] 'book'
Shanghainese[12] [ly̠³] 'donkey'
Danish Standard[14][15] synlig [ˈsy̠ːnli] 'visible' Near-front.[14][15] See Danish phonology
Dutch Standard[16][17] fuut About this sound [fy̠t] 'grebe' Near-front,[16][17] also described as near-close [ʏ].[18] The Standard Northern realization has also been described as near-close central [ʉ̞].[19] See Dutch phonology
Antwerpian accent[20] hut [ɦyt] 'hut' Regional realization of /ʏ/; lower [ʏ̞ ~ ɵ] in Belgian Standard Dutch.[16][21] See Dutch phonology
English General South African[22] few [fjyː] 'few' Some younger speakers, especially females. Others pronounce a more central vowel [ʉː].[22] See South African English phonology
Multicultural London[23] May be back [] instead.[23]
Scouse[24] May be central [ʉː] instead.
Ulster[25] Long allophone of /u/; occurs only after /j/.[25] See English phonology
Estonian[26] üks [y̠ks] 'one' Near-front.[26] See Estonian phonology
Finnish[27][28] yksi [ˈy̠ksi] 'one' Near-front.[28] See Finnish phonology
Faroese[29] mytisk [ˈmyːtɪsk] 'mythological' Appears only in loanwords.[30] See Faroese phonology
French[31][32] chute About this sound [ʃyt̪] 'fall' The Parisian realization has been also described as near-close [ʏ].[33] See French phonology
German Standard[34][35] über About this sound [ˈʔy̠ːbɐ] 'over' Near-front.[34][35] See Standard German phonology
Many speakers[36] schützen [ˈʃyt͡sn̩] 'protect' The usual realization of /ʏ/ in Switzerland, Austria, and parts of western Germany (Swabia, Palatinate, Ruhrgebiet).[36] See Standard German phonology
Greek Tyrnavos[37] σάλιο / salio [ˈsäly] 'saliva' Corresponds to /jo/ in Standard Modern Greek.[37]
Hungarian[38] tű [t̪y̠ː] 'pin' Near-front.[38] See Hungarian phonology
Iaai[39] ûû [y̠ː] 'quarrel' Near-front.[39]
Korean /gwi [ky] 'ear' Koreans tend to pronounce as diphthong 'wi'. See Korean phonology
Limburgish[40][41] bruudsje [ˈbʀ̝y̠t͡ʃə] 'breadroll' Near-front.[40][41] The example word is from the Maastrichtian dialect.
Lombard[42] Most dialects[42] ridüü


[ri'dy:] 'laughed' [42]
Low German[43] für / fuur [fyːɐ̯] 'fire'
Luxembourgish[44] Hüll [hyl] 'envelope' Occurs only in loanwords.[44] See Luxembourgish phonology
Mongolian[45] түймэр / tüimer [tʰyːmɘɾɘ̆] 'prairie fire'
Norwegian Urban East[46] hus [hy̠ːs] 'house' Near-front;[46] typically transcribed in IPA with ⟨ʉː⟩. Also described as central [ÿː].[47][48] See Norwegian phonology
Plautdietsch Canadian Old Colony[49] buut [by̠ːt] 'builds' Near-front; corresponds to back [u] in other varieties.[49]
Portuguese Azorean[50] figura [fiˈɣy̠ɾə] 'figure' Near-front. Stressed vowel, fronting of original /u/ in some dialects.[50] See Portuguese phonology
Peninsular[51] tudo [ˈt̪y̠ðu] 'all'
Brazilian[52] déjà vu [d̪e̞ʒɐ ˈvy] 'déjà vu' Found in French and German loanwords. Speakers may instead use [u] or [i]. See Portuguese phonology
Ripuarian Kerkrade dialect[53] nuus [nyːs] [translation needed]
Saterland Frisian[54][55] wüül [vy̠ːl] 'wanted' (v.) Near-front.[55]
Swedish Central Standard[56] ut [yːt̪] 'out' Often realized as a sequence [yβ̞] or [yβ].[57][58] The height has been variously described as close [yː][56] and near-close [ʏː].[59][60] It may differ from /ʏ/ only by the type of rounding and length.[57] Typically transcribed in IPA with ⟨ʉː⟩; it is central [ʉː] in other dialects. See Swedish phonology
Turkish[61][62] güneş [ɟy̠ˈn̪e̞ʃ] 'sun' Near-front.[61] See Turkish phonology
West Frisian[63] út [yt] 'out' See West Frisian phonology

Close front protruded vowel

Close front protruded vowel

Catford notes that most languages with rounded front and back vowels use distinct types of labialization, protruded back vowels and compressed front vowels. However, a few languages, such as Scandinavian ones, have protruded front vowels. One of these, Swedish, even contrasts the two types of rounding in front vowels (see near-close near-front rounded vowel, with Swedish examples of both types of rounding).

As there are no diacritics in the IPA to distinguish protruded and compressed rounding, an old diacritic for labialization, ⟨  ̫⟩, will be used here as an ad hoc symbol for protruded front vowels. Another possible transcription is ⟨⟩ or ⟨⟩ (a close front vowel modified by endolabialization), but this could be misread as a diphthong.

Acoustically, this sound is "between" the more typical compressed close front vowel [y] and the unrounded close front vowel [i].


  • Its vowel height is close, also known as high, which means the tongue is positioned as close as possible to the roof of the mouth without creating a constriction that would be classified as a consonant.
  • Its vowel backness is front, which means the tongue is positioned as far forward as possible in the mouth without creating a constriction that would be classified as a consonant. Note that rounded front vowels are often centralized, which means that often they are in fact near-front.
  • Its roundedness is protruded, which means that the corners of the lips are drawn together, and the inner surfaces exposed.


Language Word IPA Meaning Notes
Norwegian Urban East[64] syd [sy̫ːd] 'south' Also described as near-close near-front [ʏ̫ː].[65][66] It can be diphthongized to [yə̯].[67] See Norwegian phonology
Swedish Central Standard[68][69] yla [²y̫ːlä] 'howl' Often realized as a sequence [y̫ɥ̫] or [y̫ɥ̫˔][57][69] (hear the word: About this sound [²y̫ɥ̫lä]); it may also be fricated [y̫ᶻː] or, in some regions, fricated and centralized ([ʉᶻː]).[70] See Swedish phonology

See also


  1. ^ While the International Phonetic Association prefers the terms "close" and "open" for vowel height, many linguists use "high" and "low".
  2. ^ Geoff Lindsey (2013) The vowel space, Speech Talk
  3. ^ Donaldson (1993), p. 2.
  4. ^ a b Mokari & Werner (2016), p. ?.
  5. ^ a b Traunmüller (1982), cited in Ladefoged & Maddieson (1996:290)
  6. ^ Ternes (1992), pp. 431, 433.
  7. ^ Recasens (1996), p. 69.
  8. ^ Lee & Zee (2003), pp. 110–111.
  9. ^ Duanmu (2007), pp. 35–36.
  10. ^ Lee & Zee (2003), p. 110.
  11. ^ Zee (1999), p. 59.
  12. ^ a b Chen & Gussenhoven (2015), p. 328.
  13. ^ Zee (1999), pp. 59–60.
  14. ^ a b Grønnum (1998), p. 100.
  15. ^ a b Ladefoged & Johnson (2010), p. 227.
  16. ^ a b c Verhoeven (2005), p. 245.
  17. ^ a b Gussenhoven (2007), p. 30.
  18. ^ Collins & Mees (2003), p. 132.
  19. ^ Gussenhoven (1992), p. 47.
  20. ^ Verhoeven (2005), p. 246.
  21. ^ Collins & Mees (2003), p. 128.
  22. ^ a b Lass (2002), p. 116.
  23. ^ a b Gimson (2014), p. 91.
  24. ^ Watson (2007), p. 357.
  25. ^ a b Jilka, Matthias. "Irish English and Ulster English" (PDF). Stuttgart: Institut für Linguistik/Anglistik, University of Stuttgart. p. 6. Archived from the original (PDF) on 21 April 2014. 
  26. ^ a b Asu & Teras (2009), p. 368.
  27. ^ Iivonen & Harnud (2005), pp. 60, 66.
  28. ^ a b Suomi, Toivanen & Ylitalo (2008), p. 21.
  29. ^ Árnason (2011), pp. 68, 74.
  30. ^ Árnason (2011), p. 75.
  31. ^ Fougeron & Smith (1993), p. 73.
  32. ^ Lodge (2009), p. 84.
  33. ^ Collins & Mees (2013), p. 225.
  34. ^ a b Kohler (1999), p. 87.
  35. ^ a b Dudenredaktion, Kleiner & Knöbl (2015), p. 34.
  36. ^ a b Dudenredaktion, Kleiner & Knöbl (2015), p. 64.
  37. ^ a b c Trudgill (2009), pp. 86–87.
  38. ^ a b Szende (1994), p. 92.
  39. ^ a b Maddieson & Anderson (1994), p. 164.
  40. ^ a b Gussenhoven & Aarts (1999), p. 159.
  41. ^ a b Peters (2006), p. 119.
  42. ^ a b c Loporcaro, Michele (2015). Vowel Length from Latin to Romance. Oxford University Press. pp. 93–96. ISBN 978-0-19-965655-4. 
  43. ^ Prehn (2012), p. 157.
  44. ^ a b Gilles & Trouvain (2013), p. 72.
  45. ^ Iivonen & Harnud (2005), pp. 62, 66–67.
  46. ^ a b Vanvik (1979), pp. 13, 18.
  47. ^ Strandskogen (1979), pp. 15, 21.
  48. ^ Popperwell (2010), pp. 16, 29.
  49. ^ a b Cox, Driedger & Tucker (2013), pp. 224–245.
  50. ^ a b Variação Linguística no Português Europeu: O Caso do Português dos Açores (in Portuguese)
  51. ^ Portuguese: A Linguistic Introduction – by Milton M. Azevedo Page 186.
  52. ^ (in Portuguese) The perception of German vowels by Portuguese-German bilinguals: do returned emigrants suffer phonological erosion? Pages 57 and 68.
  53. ^ Stichting Kirchröadsjer Dieksiejoneer (1997), p. 16.
  54. ^ Fort (2001), p. 411.
  55. ^ a b Peters (2017), p. ?.
  56. ^ a b Riad (2014), pp. 27–28.
  57. ^ a b c Engstrand (1999), p. 141.
  58. ^ Riad (2014), p. 28.
  59. ^ Engstrand (1999), p. 140.
  60. ^ Rosenqvist (2007), p. 9.
  61. ^ a b Zimmer & Orgun (1999), p. 155.
  62. ^ Göksel & Kerslake (2005), p. 11.
  63. ^ Tiersma (1999), p. 11.
  64. ^ Vanvik (1979), pp. 13, 19.
  65. ^ Strandskogen (1979), pp. 15, 23.
  66. ^ Popperwell (2010), pp. 32, 34.
  67. ^ Vanvik (1979), p. 19.
  68. ^ Engstrand (1999), pp. 140–141.
  69. ^ a b Riad (2014), p. 26.
  70. ^ Riad (2014), p. 21.


  • Árnason, Kristján (2011), The Phonology of Icelandic and Faroese, Oxford University Press, ISBN 978-0-19-922931-4 
  • Asu, Eva Liina; Teras, Pire (2009), "Estonian", Journal of the International Phonetic Association, 39 (3): 367–372, doi:10.1017/s002510030999017x 
  • Chen, Yiya; Gussenhoven, Carlos (2015), "Shanghai Chinese", Journal of the International Phonetic Association, 45 (3): 321–327, doi:10.1017/S0025100315000043 
  • Collins, Beverley; Mees, Inger M. (2003) [First published 1981], The Phonetics of English and Dutch (PDF) (5th ed.), Leiden: Brill Publishers, ISBN 9004103406 
  • Collins, Beverley; Mees, Inger M. (2013) [First published 2003], Practical Phonetics and Phonology: A Resource Book for Students (3rd ed.), Routledge, ISBN 978-0-415-50650-2 
  • Cox, Cristopher; Driedger, Jacob M.; Tucker, Benjamin V. (2013), "Mennonite Plautdietsch (Canadian Old Colony)", Journal of the International Phonetic Association, 43 (2): 221–229, doi:10.1017/S0025100313000121 
  • Donaldson, Bruce C. (1993), "1. Pronunciation", A Grammar of Afrikaans, Mouton de Gruyter, pp. 1–35, ISBN 9783110134261 
  • Duanmu, San (2007) [First published 2000], The Phonology of Standard Chinese (2nd ed.), Oxford: Oxford University Press, ISBN 978-0-19-921578-2 
  • Dudenredaktion; Kleiner, Stefan; Knöbl, Ralf (2015) [First published 1962], Das Aussprachewörterbuch (in German) (7th ed.), Berlin: Dudenverlag, ISBN 978-3-411-04067-4 
  • Engstrand, Olle (1999), "Swedish", Handbook of the International Phonetic Association: A Guide to the usage of the International Phonetic Alphabet, Cambridge: Cambridge University Press, pp. 140–142, ISBN 0-521-63751-1 
  • Fort, Marron C. (2001), "36. Das Saterfriesische", in Munske, Horst Haider; Århammar, Hans, Handbook of Frisian studies, Tübingen: Max Niemeyer Verlag GmbH, pp. 409–422, ISBN 3-484-73048-X 
  • Fougeron, Cecile; Smith, Caroline L. (1993), "French", Journal of the International Phonetic Association, 23 (2): 73–76, doi:10.1017/S0025100300004874 
  • Gilles, Peter; Trouvain, Jürgen (2013), "Luxembourgish" (PDF), Journal of the International Phonetic Association, 43 (1): 67–74, doi:10.1017/S0025100312000278 
  • Gimson, Alfred Charles (2014), Cruttenden, Alan, ed., Gimson's Pronunciation of English (8th ed.), Routledge, ISBN 9781444183092 
  • Göksel, Asli; Kerslake, Celia (2005), Turkish: a comprehensive grammar (PDF), Routledge, ISBN 978-0415114943, archived from the original (PDF) on 26 November 2014 
  • Green, W.A.I. (1990), "7 The Dialects of the Palatinate (Das Pfälzische)", in Russ, Charles, The Dialects of Modern German: A Linguistic Survey, Abingdon: Routledge, pp. 241–264, ISBN 0-415-00308-3 
  • Grønnum, Nina (1998), "Illustrations of the IPA: Danish", Journal of the International Phonetic Association, 28 (1 & 2): 99–105, doi:10.1017/s0025100300006290 
  • Gussenhoven, Carlos; Aarts, Flor (1999), "The dialect of Maastricht" (PDF), Journal of the International Phonetic Association, University of Nijmegen, Centre for Language Studies, 29: 155–166, doi:10.1017/S0025100300006526 
  • Gussenhoven, Carlos (2007), Wat is de beste transcriptie voor het Nederlands? (PDF) (in Dutch), Nijmegen: Radboud University, archived (PDF) from the original on 25 March 2017 
  • Iivonen, Antti; Harnud, Huhe (2005), "Acoustical comparison of the monophthong systems in Finnish, Mongolian and Udmurt", Journal of the International Phonetic Association, 35 (1): 59–71, doi:10.1017/S002510030500191X 
  • Khan, Sameer ud Dowla; Weise, Constanze (2013), "Upper Saxon (Chemnitz dialect)" (PDF), Journal of the International Phonetic Association, 43 (2): 231–241, doi:10.1017/S0025100313000145 
  • Kohler, Klaus J. (1999), "German", Handbook of the International Phonetic Association: A guide to the use of the International Phonetic Alphabet, Cambridge: Cambridge University Press, pp. 86–89, ISBN 0-521-65236-7 
  • Ladefoged, Peter; Maddieson, Ian (1996). The Sounds of the World's Languages. Oxford: Blackwell. ISBN 0-631-19814-8. 
  • Lass, Roger (2002), "South African English", in Mesthrie, Rajend, Language in South Africa, Cambridge University Press, ISBN 9780521791052 
  • Lee, Wai-Sum; Zee, Eric (2003), "Standard Chinese (Beijing)", Journal of the International Phonetic Association, 33 (1): 109–112, doi:10.1017/S0025100303001208 
  • Lodge, Ken (2009), A Critical Introduction to Phonetics, Continuum International Publishing Group, ISBN 978-0-8264-8873-2 
  • Maddieson, Ian; Anderson, Victoria (1994), "Phonetic Structures of Iaai" (PDF), UCLA Working Papers in Phonetics, Los Angeles: UCLA, 87: Fieldwork Studies of Targeted Languages II: 163–182 
  • Mokari, Payam Ghaffarvand; Werner, Stefan (2016), Dziubalska-Kolaczyk, Katarzyna, ed., "An acoustic description of spectral and temporal characteristics of Azerbaijani vowels", Poznań Studies in Contemporary Linguistics, 52 (3), doi:10.1515/psicl-2016-0019 
  • Peters, Jörg (2006), "The dialect of Hasselt", Journal of the International Phonetic Association, 36 (1): 117–124, doi:10.1017/S0025100306002428 
  • Peters, Jörg (2017), "Saterland Frisian", Journal of the International Phonetic Association, doi:10.1017/S0025100317000226 
  • Popperwell, Ronald G. (2010) [First published 1963], Pronunciation of Norwegian, Cambridge University Press, ISBN 978-0-521-15742-1 
  • Prehn, Maike (2012). Vowel quantity and the fortis-lenis distinction in North Low Saxon (PDF) (PhD). Amsterdam: LOT. ISBN 978-94-6093-077-5. 
  • Recasens, Daniel (1996), Fonètica descriptiva del català: assaig de caracterització de la pronúncia del vocalisme i el consonantisme català al segle XX (2nd ed.), Barcelona: Institut d'Estudis Catalans, ISBN 978-84-7283-312-8 
  • Riad, Tomas (2014), The Phonology of Swedish, Oxford University Press, ISBN 978-0-19-954357-1 
  • Rosenqvist, Håkan (2007), Uttalsboken: svenskt uttal i praktik och teori, Stockholm: Natur & Kultur, ISBN 978-91-27-40645-2 
  • Stichting Kirchröadsjer Dieksiejoneer (1997) [1987], Kirchröadsjer Dieksiejoneer (2nd ed.), Kerkrade: Stichting Kirchröadsjer Dieksiejoneer, ISBN 90-70246-34-1 
  • Strandskogen, Åse-Berit (1979), Norsk fonetikk for utlendinger, Oslo: Gyldendal, ISBN 82-05-10107-8 
  • Suomi, Kari; Toivanen, Juhani; Ylitalo, Riikka (2008), Finish sound structure, ISBN 978-951-42-8983-5 
  • Szende, Tamás (1994), "Hungarian", Journal of the International Phonetic Association, 24 (2): 91–94, doi:10.1017/S0025100300005090 
  • Ternes, Elmar (1992), "The Breton language", in MacAulay, Donald, The Celtic Languages, Cambridge University Press, pp. 371–452, ISBN 0-521-23127-2 
  • Tiersma, Peter Meijes (1999) [First published 1985 in Dordrecht by Foris Publications], Frisian Reference Grammar (2nd ed.), Ljouwert: Fryske Akademy, ISBN 90-6171-886-4 
  • Traunmüller, Hartmut (1982), "Vokalismus in der westniederösterreichischen Mundart.", Zeitschrift für Dialektologie und Linguistik, 2: 289–333 
  • Trudgill, Peter (2009), "Greek Dialect Vowel Systems, Vowel Dispersion Theory, and Sociolinguistic Typology", Journal of Greek Linguistics, 9 (1): 80–97, doi:10.1163/156658409X12500896406041 
  • Vanvik, Arne (1979), Norsk fonetikk, Oslo: Universitetet i Oslo, ISBN 82-990584-0-6 
  • Verhoeven, Jo (2005), "Belgian Standard Dutch", Journal of the International Phonetic Association, 35 (2): 243–247, doi:10.1017/S0025100305002173 
  • Watson, Kevin (2007), "Liverpool English" (PDF), Journal of the International Phonetic Association, 37 (3): 351–360, doi:10.1017/s0025100307003180 
  • Zee, Eric (1999), "Chinese (Hong Kong Cantonese)", Handbook of the International Phonetic Association: A guide to the use of the International Phonetic Alphabet, Cambridge: Cambridge University Press, pp. 58–60, ISBN 0-521-65236-7 
  • Zimmer, Karl; Orgun, Orhan (1999), "Turkish", Handbook of the International Phonetic Association: A guide to the use of the International Phonetic Alphabet (PDF), Cambridge: Cambridge University Press, pp. 154–158, ISBN 0-521-65236-7 
Retrieved from ""
This content was retrieved from Wikipedia :
This page is based on the copyrighted Wikipedia article "Close front rounded vowel"; it is used under the Creative Commons Attribution-ShareAlike 3.0 Unported License (CC-BY-SA). You may redistribute it, verbatim or modified, providing that you comply with the terms of the CC-BY-SA