Stray cats in South Korea are known as 길고양이 or “road cats” (meaning stray cats). Until very recently Koreans didn’t really keep pets; dogs were for protection and cats were use-less in general. Now everybody wants a pet, until they are no longer fun, which is when they get “released” into the street. Cats and dogs have become real pests, killing the local wildlife.
However some people do sympathize with the “road cats” and have organized welfare groups using “My Own Stamp” (나만의우표) personalized labels to raise awareness and money to help feed these homeless and wretched cats. A cat-lover makes a set of labels each month with the slogan 고양이는 고양이다 (“A cat is a cat”), meaning every cat is valuable.
Here are some recent examples of these sheets from the account “ckfzkrl” (김하연) on Deskgram:
The series has been going on for quite some years now. Here are two examples from 2007 using the then current form of the My Own Stamp option. Notice that at this time you didn’t actually get your own stamp but your own stamp label (seal, cinderella). This is different from today. Nowadays when ordering your own stamps you get real stamps, with their own postal validity.