[1.5.1.1] UPC Truncated when EAN used VARCHAR(12)

I'm using the EAN barcode as my UPC when entering products into OpenCart- This maps, using the pre-installed google base feed in Opencart 1.5.1.1 to Google's attribute UPC, an attribute of ever increasing importance as far as Google seem to be concerned.

In the UK EAN barcodes are usually 13 characters. The upc field in the products table is defined as varchar(12). When I enter my 13 digit EAN's they are truncated to 12 characters.

I have changed the upc field in my database to be varchar(16). Now I can add my full EAN's without them being truncated.

Would it be possible to redefine the UPC field to accommodate longer values in future releases? Will my change have any negative effects?

Thanks
Rob

Edit: I mixed my terms a little. Google refer to this attribute as Unique product identifier, that can be a UPC or an EAN etc. See Google's Unique product identifier spec it looks like the longest value is 14 characters.

Thanks for the heads up on this.

Shouldn't have any negative effects.

Will update my extension to add this to the readme.

Thanks for putting my mind at ease, always nice to have someone else confirm these sorts of things are acceptable!