Princess Catherine has released a very special letter which sparked comments from eagle-eyed royal fans. The 43-year-old released a letter for The Forward Trust’s Taking Action on Addiction Campaign to support Addiction Awareness Week on Monday.

As well as a personal message, Catherine also used her rarely-used cypher to sign off the solo letter. The royal currently stands as patron of The Forward Trust, a British charity working to support individuals impacted by addiction, crime, homelessness or long-term unemployment, and spearheaded the first Addiction Awareness Week in 2021.

Released on November 24, the letter read: “This Addiction Awareness Week, I am, as always, very glad to lend my support to this hugely important campaign.

“Through my role as Patron of the Forward Trust, it has been humbling to see the significant progress made to better understand addiction and tackle the stigma surrounding it, but there remains much more to do.”

Placed at the top of the letter was her own personal Kensington Palace letterhead, which was stamped in gold.

The symbol, which has been referred to as rare, showed a ‘C’ for Catherine placed below a crown, over ‘Kensington Palace’.

Taking to X after noticing the ‘C’, fans were keen to point out that Catherine is her full name – and that it is “not rare or new”.

One fan commented: “Maybe because her name is Catherine? And it’s not rare. That’s how she always signs her name…”

As well as another pointing out that it “not rare or new”, a third fan commented: “Where have you been for 20 years? Her parents named her and called her Catherine, she graduated as Catherine…”

A fourth added: “Did you know that her name is Catherine? That she always signs her correspondence only with her name, without titles?…”