GenoPro has a built-in algorithm to detect duplicate records and merge them together.   This features saves space (memory) while providing a better understanding of the structure of the family tree. This feature was originally written to merge identical pictures.  Later, this code was used to merge identical places, sources, pictures, unions, occupations and education records.  Those objects were always kept regardless of their use.  For instance, if you enter a place name, and make a typo, then the old place name would remain in the document even if no longer used.  I saw documents having several thousand of those objects, obviously not wanted since they were all typos.  The decision was made to automatically cleanup those "stray objects" when saving.

There is no easy solution to this dillemma, and if you have suggestions, feel free to share them with us. Perhaps one solution would be having an option in the place object for "not deleting automatically if unused".

In the meantime, a workaround is to create a dummy individual and assign all the places you want to keep.

You are welcome to read Source vanishing when saving.

I took a note in my todo list to have an option to "Automatically delete stray objects on save".  By default, this option would be on because if it is off, the .gno file would contain a ton of garbage and most people would be afraid to use this option.  Few people are willing to use a "delete" function they don't understand.

I think this option should follow the .gno document rather than the computer.  This would be safer than storing this option in the computer registry where all the documents would be subject to this option when saving.

I agree with you.  On the other hand, I saw countless family trees with hundred of those places and source records that were junk.  Nobody was willing to delete those objects.  The philosophy is: if an object such as a place or picture is not used, then it may be deleted.  This is not a perfect scenario, however it is a good compromise.

Of course GenoPro could be smarter and try to detect the quality of the object being deleted.  There is a lot of work to be done in this area.  For instance, merging identical Union records is still open to debate.  I am not sure myself which is the best way to go about this.  See post Same marriage union record for several families.

That's what the option "Delete Stray Objects" at the bottom of the menu Table Layout is about.  The dialog to delete the unused objects displays a list of all the 'junk records'.