The National Library of Wales lacked about 2,200 items, an increase of 84% in two years.
In the archives and manuscripts, what is missing are the deeds of the 13th century Powis Castle, as well as the "Rouss" and "Generation" files from Gwrych Castle in Abergele, Conway County, hosting ITV twice is my celebrity... Let me get out of here!
Missing books include the history of the National Library, among books by Aberystwyth, Ceredigion, Daniel Huws and George Bernard Shaw and Virginia Woolf.
The library is creating a new “Collection Nursing” division, which is currently recruiting heads of the division as well as unique collection leaders.
The unprompt figures are significantly higher than the 1,200 items missing from BBC Wales’ free information requests obtained through September 2023.
A spokesman said the increase was due to "a new stock check process."
The library is a legal deposit library, meaning it has the right to obtain copies of every printed publication in the UK and Ireland and does not allow any items to be taken out of the building.
Of the 2,206 missing projects, according to the request of the BBC Wales’ latest Freedom of Information Act:
Missing archives include the papers of J Glyn Davies, whose children's songs include Cerddi Huw Puw (1923), based on the sailor songs he heard in his youth.
These are described as "marks of genius."
Documents related to Chilk Castle near Wrexham were also lacking, and the construction of the paper began around 1295 during the reign of Edward I.
The missing sound recordings include Dafydd Iwan's satirical song "Carlo", written for Charles in 1969 as the Prince of Wales, and the recordings by Treorchy Male Choir.
Missing journals include the library's own journal, the Welsh History Review, the Flintshire Historical Society, the local history of Gitt and the Carmason historians' questions.
The missing books cover the subject of Owain Glyndŵr, the last locally born Welsh prince of Wales, a biography of Keir Hardie, the first Labour parliamentary leader.
Mark Akenside's 1818 edition of The The The The The The The The The The The The The The Pleasures of Imagination'' (Mark Akenside) and Mrs. Charlotte Schreiber's journal (1911) were also missing, which is the "confidence" of collectors of ceramics and antiques.
A book by Phil Thompson and Tommy Smith called "Being Another Son, I Will Break Your Legs: The Hard Man of Football" is also not explained.
Missing maps include the Malt Whiskey map of Scotland, as well as several maps related to Gogerdan, the main property of the Old County of the 17th century.
Rhodri AP Dyfrig, head of communications at the library, said the staff “has introduced a new inventory checking process for published collections, so we fully expect the items recorded to increase because they won’t be incorrect in their correct locations”.
He added: “The thorough process of monitoring misplaced items is constantly happening, and these inspections are a normal and part of maintaining good practice in the standards and library fields.
“Due to this constant surveillance and work, the data we provide is a snapshot of a specific period and the number fluctuates regularly as projects are discovered and relocated.”
The library conducts annual reviews of items worth over £10,000 per year and has not found any missing items for that threshold in the past year.
The library's collection includes 7 million books and newspapers, 1.5 million maps and 950,000 photos, located on 160 miles of shelves.
The Welsh Government said: “The care and management of its collections is a problem with the National Library.
“Doing so, it complies with the certification of Archive Services – UK-wide Archive Services Standards.”