Duke of Marmalade
Imperial Majesty
- Joined
- May 19, 2007
- Messages
- 14,624
- City
- Frankfurt am Main
- Country
- Germany
https://en.wikipedia.org/wiki/Substantive_title
- The title is only officially borne by one person at a time
- The title is ceremonial and confers no political, territorial or civic prerogative as such
I guess it only means the title is particularly given to the heir? (and probably they just copied from wiki as I saw the exactly same sentence appears)
Leonor became Princess of Asturias when her father became King, before her mother was addressed as Princess of Asturias as wife of the Prince of Asturias.
Here has been some discussion going on in a different thread, titles of future husbands, when Leonor gets married and her father is still King, her husband will become Prince of Asturias.