What does the " |%15d| " do again?

[Yourhighness]

Hey guys,
just trying to remember what the ' | ' does in relation to using printf.
Eg:

printf( "|%15d|", somevariable );

I know I could probably write a program, but that shows me what it does and not necessarily explain what it does. Esspecially with the example we were given, being more complex than the above. Cheers,
Johannes

[Yourhighness]

Thanks for that. I think i got confused because there are some where you have to put like a '%' or '\' and I had a look at those just before that. So no comments on the printout from the lecture didnt help me. Now I know. Cheers for that,
Johannes