func (id ID) Tag() language.Tag {
	if int(id) >= len(coreTags) {
		return specialTags[int(id)-len(coreTags)]
	}
	return coreTags[id].Tag()
}

var specialTags []language.Tag

func init() {
	tags := strings.Split(specialTagsStr, " ")
	specialTags = make([]language.Tag, len(tags))
	for i, t := range tags {
		specialTags[i] = language.MustParse(t)
	}

				t, _ = t.SetTypeForKey("va", variant)
				hasExtra = true
			}
			exact = old == t
		} else {
			exact = false
		}
		if hasExtra {
			// We have some variants.
			for i, s := range specialTags {
				if s == t {
					return ID(i + len(coreTags)), exact
				}
			}
			exact = false
		}
	}
	if x, ok := getCoreIndex(t); ok {
		return x, exact
	}
	exact = false