I may be mistaken but It seems like the only ones who actually use the titles when giving a personal comment from them are The TOS and ILBW
Catherines letter to the hospices had no titles just header that says Kensington Palace and is just signed with her first name and the welcome to royal ascot from the King and queen is styled the same way no titles just a header that says Windsor Castle![Two hearts :two_hearts: 💕](https://cdn.jsdelivr.net/gh/joypixels/emoji-assets@5.0/png/64/1f495.png)
Catherines letter to the hospices had no titles just header that says Kensington Palace and is just signed with her first name and the welcome to royal ascot from the King and queen is styled the same way no titles just a header that says Windsor Castle
![Two hearts :two_hearts: 💕](https://cdn.jsdelivr.net/gh/joypixels/emoji-assets@5.0/png/64/1f495.png)