Hm, I looked through my (still small) batch of postcards again, and of course, there the code is, especially on US postcards- sometimes directly printed on the card if most of this area is left blank, and sometimes on the white strip
Oh no! No, seriously: thank you for the explanation! Now I know how to go about that, and that it is not much of a problem if I need that space e.g. for longer texts. Still will be careful when sending one of those cards to the US
Quite a few other countries are printing a code in that area too it seems, but none of them seem to be bothered when the area is covered in text, stickers, or even washi tape the whole length- they just print the code right over all of those
I always wondered if the barcodes, when on the bottom of the card, interferes with the machines doing the mail sorting. Like, does it slow the machine down, or does the machine just ignore it?
usually the sorting code for processing is not just ordinary black ink, that in fact would interfere with codes already on it. Most use a special ink, for example some type of fluorescent, that way it’s not sticking out for the human eye, but machine read it creates a good contrast regardless of most backgrounds or images going on. I’ve also had cards, where the code somehow ended up on the image side of the card (only), and that also didn’t present an issue, as it clearly arrived.
German Post theoretically requires the bar down below also to stay empty because of this. But it never was any problem, and since my pen can not interfere with their markings I usually don’t bother about keeping it free…
I always cover barcodes with stickers. But to be honest, lots of my stickers are to short or have the form of feathers, birds, other animals and it’s impossible to cover the whole barcode. >o<
So I often use a darker slice of a washi tape to hide the barcode.
I let the text available if it’s a information about the picture on the front side, because I also would read it myself when I got a postcard. Even it’s in non-latin letters.
I also don’t cover the text on the bottom because of the post machine in germany. We aren’t allowed to use sticker or anything else at the very bottom of the postcards. But some of my postcards have ugly barcodes on the very bottom left or right side and I always want to cover it. >_<
No, seriously: thank you for the explanation! Now I know how to go about that, and that it is not much of a problem if I need that space e.g. for longer texts. Still will be careful when sending one of those cards to the US 
