https://www.php.net/manual/uk/intlchar.isupper.php
PHP: IntlChar::isupper - Manual
Check if code point has the general category "Lu" (uppercase letter)
phpmanual
https://moscot.readthedocs.io/en/latest/developer/genapi/moscot.utils.tagged_array.Tag.isupper.html
moscot.utils.tagged_array.Tag.isupper - moscot documentation
moscotutilstaggedarraydocumentation