Almost every product found in a US grocery store is labeled with both imperial and metric units of measurement.
Some products are marked with a stylized lowercase “e” before the metric measurements, like:
12 fl oz e 355 ml
The “e” is always the same typeface on every product, no matter what typeface the measurement is is. The “e” is also always a larger point size than the typeface used for the measurement.
What does that “e” mean? Why is it always in that same typeface?
If that was the case, why is is on products that aren’t labeled in English, or on products that don’t have imperial measurements? Why is the font of the “e” the same on every product?
The E symbol indicates that it comes under the " average " packaging rule . This means that individual items do not have to match the exact weight or volume indicated on the pack, but the average of a batch of them must do.
Here are the regulations.
The Act also contains type size requirements for indications of both weight and volume, and provides for the ‘average’ system of quantity control for pre-packed goods, which is designed primarily for application at the point of production or importation and which is indicated next to the weight declaration on the pack by the symbol “e”. It requires the packer or importer to ensure that the packages will pass an Inspector’s reference test.
I seem to recall that “e” is an abbreviation for “einhalt,” which is German for “contents.” I googled around but couldn’t find a cite for this. I did find some more details on EU labeling regulations – in particular there’s this paragraph on the “e” mark.