"in 24 hours unless flagged"

What that mean?

(post withdrawn by author, will be automatically deleted in 24 hours unless flagged)

  • If it is flagged, it will be deleted instantly?
  • If it is flagged, it will not be deleted?

Maybe it may be reworded. Thanks.

When you flag a post, it triggers moderator’s attention. So depending on moderator’s availability, it could be acted on immediately or later.
The fact that the post is deleted or not depends on the flag selected.
To know more about flags, see:

After reading your answer and a lot more on meta.discourse, I understand that, if it is flagged, it could be deleted instantly (“depending on moderator’s availability” or the user’s trust level) or could not be deleted (a moderator decision). If it is this way, no need to rewording.