How to suppress pop-up and what is an "abbreviation"??

[kpl1949 0]

Hello, in evernote (online) there appears a dark pop-up window (about "my notebook" ... which does not disappear. How to remove this message window???

And: What is an "abbreviation" (German: "Abkürzung") and what do I do with it??? See screenshot.

 

Thanks.

 

Klaus Luecke