Complex sentence: This appointment grants the post-nominal letters KNZM and allows the appointee to style themselves as Sir Roderick and his wife as Lady Deane or collectively as Sir Roderick and Lady Deane.
Split into simpler sentences: This appointment grants the post-nominal letters KNZM and allows the appointee to style themselves as Sir Roderick. The wife of a Knight is addressed as Lady Deane or collectively as Sir Roderick and Lady Deane.