GB Stamps and Errors

Question: What is an Error?
Simple Answer: ANY type of mistake/s that occur during printing process.
All stamps sold Unmounted Mint (UMM).
Since 1973 until 1993 collection of Queen Elizabeth ll (QE 2) United Kingdom Decimal Stamps of Great Britain have revealed all sorts of errors, flaws, phosphor shifts, colour shifts plus varieties in our collection.
In 2022 new Stamps were inroduced with Barcodes. This also have errors and flaws.
These GB Stamps & Errors have been Catalogued by:
Stanley Gibbons 
MBPC
MCC
Stoneham
Deegam
Those errors that have skipped the above, we have catalogued them under the description title of Newly Discovered. 
These Newly Discovered stamps (ND) are from: 
New Barcoded Booklets and sheets
Vending & Counter booklets
Definitives (Machins)
Commemorative sheets
Non Value Indicator (NVI) booklets
AND
Used stamps too!