[Yaffs] How to delete a file or dir for yaffs2?

Dear all,
I read the file "HowYaffs works", but there is a detail description about
this.
For example, i create a file with object id 0x46d, then i delete it. Now it
will add object named "deleted" with object id 0x46d parent id 3 or 4,
right?
Will it reallocate the object id 0x46d to a new object later?
If so, when scanning the flash data, how to judge the new file with obj
id=0x46d is deleted or not?
BR.