Editing Template:Script/doc/id-unk/is-iso-alpha4

<!-- ISO 15924 alpha4-IDs:
 Returns input alpha4 when existing, <blank> when not existing (per #default).
 "Special ISO codes" (number 900-999) are NOT recognised here (Qaaa..Qabx, Zinh Zmth Zsye Zsym Zxxx Zyyy Zzzz).
 List of ISO codes as of 2021-02-17 (201 regular codes)
 -->{{#switch:{{{alpha4|}}}
|Adlm|Afak|Aghb|Ahom|Arab|Aran|Armi|Armn|Avst|Bali|Bamu|Bass|Batk|Beng|Bhks|Blis|Bopo|Brah|Brai|Bugi|Buhd
|Cakm|Cans|Cari|Cham|Cher|Chrs|Cirt|Copt|Cpmn|Cprt|Cyrl|Cyrs|Deva|Diak|Dogr|Dsrt|Dupl
|Egyd|Egyh|Egyp|Elba|Elym|Ethi|Geok|Geor|Glag|Gong|Gonm|Goth|Gran|Grek|Gujr|Guru
|Hanb|Hang|Hani|Hano|Hans|Hant|Hatr|Hebr|Hira|Hluw|Hmng|Hmnp|Hrkt|Hung|Inds|Ital|Jamo|Java|Jpan|Jurc
|Kali|Kana|Khar|Khmr|Khoj|Kitl|Kits|Knda|Kore|Kpel|Kthi|Lana|Laoo|Latf|Latg|Latn|Leke|Lepc|Limb|Lina|Linb|Lisu|Loma|Lyci|Lydi
|Mahj|Maka|Mand|Mani|Marc|Maya|Medf|Mend|Merc|Mero|Mlym|Modi|Mong|Moon|Mroo|Mtei|Mult|Mymr
|Nand|Narb|Nbat|Newa|Nkdb|Nkgb|Nkoo|Nshu|Ogam|Olck|Orkh|Orya|Osge|Osma|Ougr
|Palm|Pauc|Pcun|Pelm|Perm|Phag|Phli|Phlp|Phlv|Phnx|Piqd|Plrd|Prti|Psin|Ranj|Rjng|Rohg|Roro|Runr|Samr
|Sara|Sarb|Saur|Sgnw|Shaw|Shrd|Shui|Sidd|Sind|Sinh|Sogd|Sogo|Sora|Soyo|Sund|Sylo|Syrc|Syre|Syrj|Syrn
|Tagb|Takr|Tale|Talu|Taml|Tang|Tavt|Telu|Teng|Tfng|Tglg|Thaa|Thai|Tibt|Tirh|Tnsa|Toto|Ugar|Vaii|Visp|Vith
|Wara|Wcho|Wole|Xpeo|Xsux|Yezi|Yiii|Zanb={{{alpha4|}}}
|#default={{{default|}}}}}<!--
--><noinclude>{{documentation|content=

:Returns input alpha4 when existing, &lt;blank> when not existing (per #default).
:"Special ISO codes" (number 900-999) are NOT recognised here (Qaaa..Qabx, Zinh Zmth Zsye Zsym Zxxx Zyyy Zzzz).
: List of ISO codes as of 2021-02-17 (201 regular codes)
*>Adlm &rarr; {{Script/doc/id-unk/is-iso-alpha4|alpha4=Adlm}}

*>Aaaa &rarr; {{Script/doc/id-unk/is-iso-alpha4|alpha4=Aaaa}}

}}</noinclude>