This is what sync FAQ says. You'll want to read up on what sync is and isn't was well.

https://support.mozilla.org/en-US/products/firefox/backup-recovery-and-sync/sync-data

https://support.mozilla.org/en-US/kb/how-do-i-choose-what-information-sync-firefox

Thanks Mark, but I read all of that. Did not answer my question. If I missed it, please show a small quote from the docs you link. But it does not tell me how to make the PC the original template for others to follow until a change happens.

Thanks.

Those are the sync FAQ. There no such thing as what your asking it's you choose the sync options or sync everything back and forth from different computers.

I don't believe that.. First time you sync something becomes the baseline that the next device compares to. Or things might get deleted that are desired to stay. And worse, if it combines ALL bookmarks so those that are desired to be removed are now in both places.

Perhaps I am not explaining myself well enough.

First computer has bookmarks a,b,c,j,k,n Second has a,b,d,e,f,l

I set up. I sync. I want BOTH to have a,b,c,j,k,n I want neither to have d, e, f, l Worst, I do not want either to have a,b,c,d,e,f,j,k,l,n

If that is NOT how FF Sync works, then what would happen in that scenario?

Maybe you should create two separate sync accounts to keep data separate.