msd/chunk atom id constant

Dear LAMMPS users,

On the compute msd/chunk page it is mentioned that using the ids once option in compute chunk/atom will keep the atom IDs assigned to chunks constant.
The wording in the manual is slightly confusing. It's also mentioned that LAMMPS has no simple way of ensuring that atom IDs in chunks are constant.

Will choosing the ids once option make the atom IDs assigned to chunk IDs constant?

Thanks
Soumyadipta

Dear LAMMPS users,

On the compute msd/chunk page it is mentioned that using the ids once
option in compute chunk/atom will keep the atom IDs assigned to chunks
constant.
The wording in the manual is slightly confusing. It's also mentioned that
LAMMPS has no simple way of ensuring that atom IDs in chunks are constant.

​please be more specific and point out the exact pages and paragraphs​ you
are referring to. most likely, you are quoting out of context.

axel.

http://lammps.sandia.gov/doc/compute_msd_chunk.html

It's mentioned in the second note.

I also have another confusion on the same page. In the example usage, the command used is compute com/msd whereas the name of the command on the top of the page is compute msd/chunk.
Does the compute msd/chunk compute the average of msd for each atom in a chunk at regular intervals like the simple compute msd command ?

Thanks
Soumyadipta