What is the meaning of added by user slogan under some token on pancake swap dex and how to check that token added by me on pancake swap dex is available for others or not
Hi, welcome! 
Do you mean import a new token like this:
I think pancake provides user a default token list, so for some tokens, maybe it is not popular, and if you input the token symbol directly, it will not display, so if you import this token manually, it will record for you, and for the next time, you can input token symbol directly to find this token.
Add enough liquidity for your token pair, so others can trade with this pair.
But by importing the token I could see but how other people will see the same token for swapping
Sorry, I am not familiar with Pancake, but I think you can have a look at this article about Uniswap token list: