Great Britain One Pound Ten Royal Miil For Mail Error

Hi to all
This error was recently reported in a stamp magazine but unfortunately I do not remember which one.
On the second line, top left instead of saying MAIL it says MILL.
This is a nice well centred copy used on piece.
Does anyone recall the magazine and have many of them turned up?
Regards
Horamkhet.

Hi Horamkhet, This isn't an error - it's a security code: M11L.

That is correct. Other modern Machins also have various security codes (M12L, MTIL...). Below is another example with 2 security codes (MA12 at left and MR1L at right):

As Kim has noted that there are actually two codes on the stamp, a source code MAIL at the top right, and the year code, M11L.

In this case the year code for 2011, M11L (or MIIL if you prefer) is for year 2011.

The source code, just MA1L (or MAIL) in this case, identifies the stamp's source as a regular counter sheet.

There are many combinations, especially for the 1st and 2nd class values.

I believe the rarest combination so far is the blue 2nd class stamp from 2010 coils which has source code MR1L and year code MA10.

If you look for this codes please be aware that the year code isn't always in the same place. For example in the 2010 2nd class coil that I mentioned the year code is lower down, just in front of the Queen's forehead.

Nice one Kim!

Arnie will be turning in his grave.

I know that the British have always been security conscious regarding stamps. But how much of a problem is it really for them to take such precautions?

Just look at the measures on this one stamp. The back printing, the slits, and the elliptical perforations.

I would suggest the thread title is updated as this is obviously not an error.
They are plenty of online resources available which would have confirmed the Machin security overprints have year and source codes. Just google M11L stamp for example.

I would love to see the magazine article mentioned....if it exists that is.

Unfortunately, not mine. Pilfered pic.