POLITENESS AND INTERNATIONAL SIGNAGE
One challenge for making multilingual signs from Japanese adjusting levels of politeness. Would you have a sign that says 高電圧に触れないでくださいませんか? Or a sign at a register telling customers お金出せ! Computers have a difficult time translating the nuances of politeness. We recommend that when you use Higosign, you first use neutral Japanese (-desu, masu forms) and then make changes to help choose what kind of sign you want to make. 

One useful general rule is that the longer something is, the more polite it is. This is because the more effort the speaker/writer makes to say or write the message, we can think of that person as doing more 'work'. Conversely, the shorter it is, the more direct the message is and we don't want a direct message to be too long.

(chart of politeness examples here)

Signage can be unintentionally offensive, and this is an important problem to avoid. Examples of unintentionally offensive branding can be seen below. Sign 2 shows a group of entertainers in a 48-hour marathon program hosted by Fuji TV in 2015, with T-shirts with the program slogan “DO HONKY. No TV. No life.” Honky (or honkie) is a racial slur against white people, often used in contrast to the “N” word for black people. Sign 3 shows another taboo word (the “F” word) boldly used to describe a sale in XXX when
看板/表示を作成するときには注意が必要です。なぜならば、意図せずに、その言語を使う人たちにとって、失礼な表現や猥褻な表現になってしまうことがあるからです。下記の写真は、2015年にフジテレビの48時間テレビで放送された際に着用されていたTシャツです。
Sign 4. Do Honky sign.
Sign 5. Fucking sale
The choice of language used in signage is also connected with politeness. The wrong choice can be offensive within the context of the sign’s environment. Sign 4 in the women’s restroom tells the reader to keep the door closed, in Korean. However the implication is that the writer believes that only one cultural group could possibly be responsible for the transgression. Such a sign should be put up in all possible major languages, or use a universally-understood iconic image. 
表示が与える印象は、どんな言葉を用いるかに左右されます。誤った言葉の選択は読み手を侮辱することにもなりかねません。4の表示は女子トイレに表示されているもので、韓国語で読み手にドアを閉めるように指示しています。ここでは2つの問題があります。まず、このような表示は通常中国語で表示されています。なぜならば、中国語圏では、かつてトイレを使用中に、ドアを閉めることに対してあまりこだわりがありませんでした。したがって、中国語で表示するなら理解できますが、韓国語だけでこの表示をする意味はありません。しかしながら中国語で
Sign 6. -- keep door closed in Kumamoto Castle pic