https://community.usa.canon.com/t5/Desktop-Inkjet-Printers/ink-cartridge-box-numbers/m-p/126149#M4959 <P>There is a black (or now gray on newer boxes) rectangle on bottom of 240XL and 241XL ink cartridge boxes (e.g.,&nbsp;<SPAN>4914D16, 3913G16, 2A14E25, 2A14C24). &nbsp;The solid rectangle&nbsp;is to the right of the bar code. &nbsp;No one seems to know what the number means, including Canon (said it was inventory control, but I believe that's what the bar code is; maybe not .....)</SPAN></P><P>&nbsp;</P><P><SPAN>Thanks!</SPAN></P><P>&nbsp;</P> Wed, 19 Nov 2014 18:40:57 GMT maxcatz 2014-11-19T18:40:57Z https://community.usa.canon.com/t5/Desktop-Inkjet-Printers/ink-cartridge-box-numbers/m-p/126149#M4959 <P>There is a black (or now gray on newer boxes) rectangle on bottom of 240XL and 241XL ink cartridge boxes (e.g.,&nbsp;<SPAN>4914D16, 3913G16, 2A14E25, 2A14C24). &nbsp;The solid rectangle&nbsp;is to the right of the bar code. &nbsp;No one seems to know what the number means, including Canon (said it was inventory control, but I believe that's what the bar code is; maybe not .....)</SPAN></P><P>&nbsp;</P><P><SPAN>Thanks!</SPAN></P><P>&nbsp;</P> Wed, 19 Nov 2014 18:40:57 GMT https://community.usa.canon.com/t5/Desktop-Inkjet-Printers/ink-cartridge-box-numbers/m-p/126149#M4959 maxcatz 2014-11-19T18:40:57Z