Yes, the locale-gen script requires that you use the real name according to /usr/share/i18n/SUPPORTED. But once ru_RU.CP1251 has been generated, glibc recognizes both ru_RU.CP1251 and the alias ru_RU.cp1251. For instance you can confirm it with:
locale -a | grep ru
Yes, the locale-gen script requires that you use the real name according to /usr/share/ i18n/SUPPORTED. But once ru_RU.CP1251 has been generated, glibc recognizes both ru_RU.CP1251 and the alias ru_RU.cp1251. For instance you can confirm it with:
locale -a | grep ru