I have a Limited Edition LEGO set which has an embossed 4-digit (2755) number on the bottom. I'm curious to know what it is because I don't remember seeing one before. It would also be nice to know what the numbers under the barcode represent (118789 524)
If I had to guess I would say it was a unique number given to each set in the production line of the set.
That number is not a real number, it is a production code (in your case, 27S5) consisting of 2 digits indicating the week of the year the set was made (in this case, the 27th week), a letter indicating the region the box was made in/for (R = US/Canada, S = Europe, I believe) and the last digit is the last digit of the year the set was made in.
So you have a Gingerbread house made in 2015, in the 27th week of the year (June 29, 2015 - July 5, 2015), and it was produced in/for the European market.
These codes typically go on the seals/stickers closing a box, but in case of smaller boxes that are supposed to be pushed open, the code gets embossed into the package.
And just for comparison - all my Gingerbread houses have production code 31R5 (I'm in the US).
UPDATE 5/2/2016: Here is a list of all the plants referred to by the letter code:
H = Nyíregyháza, Hungary
R = Ciénega de Flores, Mexico
S = Kladno, Czech Republic
Q = Purkersdorf, Austria
B = Shenzhen, China (Not Confirmed)
M = Billund, Denmark (Not Confirmed)
O = Billund, Denmark (Not Confirmed)
Note: list attributed to GiliusThunderhead over at the BrickPicker.com forums.
I can verify that Phil B's answer is correct, based on a personal experience I just had. However, I can also add a bit of clarification on five-character codes.
I recently purchased six copies of Set #31128 at a local retailer:
I gave the sets away as Easter gifts, but two of the sets had defective instruction booklets for the main build (the Sea Turtle and Dolphin)! Here is an example of the problem:
Clearly, the issue is not a printing error. Instead, the issue stems from incorrectly stapling the wrong pages together. It appears that four pages were duplicated and stapled into the center of the booklet in place of the four pages which should have been there. In other words, Steps 8-54 were repeated. I contacted LEGO Customer Service to warn them of the error so that they could increase quality control and track down the source of the issue.
As it turned out, LEGO Customer Service quickly responded and requested that I send them a unique identification code from the boxes that contained the incorrect instruction manuals. When I asked for clarification, they explained that sets had a four- or five-character number printed either on the cardboard box next to the barcode or on the sealing tape. They explained that this number provided information regarding the date and location of the set's manufacture and assembly.
Here are three different Manufacturing Code Numbers I found on my boxed sets:
Therefore, the four-character code you found embossed on your boxed set is, in fact, an official LEGO Group Manufacturing Code Number that provides unique identifying information for the set.
However, you may note that two of the representative images I provided above actually had five-character product codes (instead of just four characters). That is because five-character codes also include the day of the week that the set was packaged. So decoding a five-character product code is as follows:
