What does "linkedin" mean?

I do not really understand the last line of each language section of

title = "My blog"
weight = 1
linkedin = "english-link"

What link do I have to enter?
Is this line mandatory?
Can anybody please help me out?

https://www.linkedin.com/ ?

May be it’s possible to have profiles in different languages?

AFAIK the urls are indeed different per Lang for LinkedIn.

You can omit if you’re not using.

LinkedIn is a business- and employment-oriented social networking service that operates via websites and mobile apps, according to Wikipedia.

If you don’t have a social profile on linked in, you don’t have to put anything there. Cheers.

Thanks for clarifying this.
I was somewhat puzzled as I thought this to be something like a page or custom variable but couldn’t find anything about what it does anywhere in the docs.

And since my approach to add a second language does not work till now I investigate every single letter of my template and markdown to find the cause.