The script
attribute specifies the writing script of a language, such
as "Cyrl". Like the xml:lang attribute, the script attribute
is allowed on all text-containing elements plus one
non-text-containing element:
langSet. Use values found for “script” in the
IANA language subtag registry. Do
not use deprecated values. You should omit the script
attribute when it makes no useful distinction (as for the
primary or sole script of a language). In particular, you
should omit the script attribute if it matches the
"Suppress-Script" field in the registry for the language you
used.