"import metadata" when importing a job from json file?

I tried to look up this info in manuals and this forum, but failed to spot it.

There are two checkboxes on the web ui page that allows me to import a job spec from a json file. These checkboxes are not explained anywhere that I know of. What are they for and how do they worrk if I have 1) exported and 2) deleted the job, 3) changed the ID number of the job in the json file I am importing anew?

I think it’s answered in this post: