I am looking to circumvent a possible problem when I start to share my information with relatives. I see that while GEDCOM is supported to some fashion by most programs, there are shortfalls in each.
The way places, names etc are recorded seem very different across programs. When the data is moved between programs (such as via GEDCOM files) the transfer is often incomplete. Is it possible for users to enter data in a way that prevents (or at least reduces) those losses?
Most genealogy programs have implemented the basic connections between people and families and the basic events and facts of the GEDCOM standard. You are usually safe with entering the standard data that most programs accept.
It is where you are dealing with more advanced features of your program where you will often have problems. If your program does something that many other programs don't do, or don't do the same way, then it is very likely that not all the data entered via that feature will transfer to other programs properly.
The most often reported set of data that usually will not transfer between programs are the citations for your source references. Programs that implement citations often choose the Mills templates, but they are not perfectly defined and each program implements them with slight differences. But worse, GEDCOM was written before citations were implemented extensively in genealogy software, so each program has invented their own way of writing citation information to GEDCOM, and few programs have implemented input of this custom GEDCOM from other programs.
There are many other data items that are affected by different implementations. The worst problem is an inconsistent implementation of the CONC (concatenate) tag in notes. If you transfer your data between two programs that export CONC tags differently, then you may find that your notes have extra spaces in the middle of a word every line or so, or may have the space between a word missing every line or so.
Your best bet to minimize these problems is to use a program that says it exports its data to GEDCOM using the 5.5.1 standard. The program should then only allow you to enter data that can be exported. And programs that say they can properly read in GEDCOM 5.5.1 should then be able to read in most of the data - at least the parts that they've implemented.
It does also future-safe your data, because any future standards that are written will have to make sure that GEDCOM 5.5.1 conversion programs will be available.
Your best bets are to:
If you plan to export to GEDCOM format, then I'd recommend using a genealogy program that does it correctly. I switched to Family Historian years ago because I could find no other package that did not corrupt my exports (FH uses GEDCOM natively so no export is necessary). To test your program, take a GEDCOM file and import it into your software, then export it back out and use a program to show the differences to see how much data is lost. This is best done with a test GEDCOM file that uses all the available fields, and then some. You would also need to test your vendor specific fields get exported correctly after some editing, but that's more difficult to assess. If your favorite package does not export your data correctly, complain to your vendor, that is the only way that vendors will bother fixing their problems.
The best way to minimize loss is to compare which events a program offers. Some have places for witnesses, GPS coordinates, DNA results, hair & eye color, etc. Sometimes these are best kept as notes rather than events, if they are to be imported into another researcher's older software.
I've noticed that notes and pictures which I've checked "never print", do not transfer into a GEDCOM. Also, when imported into other programs, the picture files appear, but don't always print in reports. In one program, I have to go in and mark which picture is the "default". Another program prints pictures which were previously marked as primary (or default), but does not print pictures without any designation. So now, I always mark them as I go.
Many programs allow the user to change the way dates and locations are presented. Others do not. I don't know if anyone has done a study of the top 12 or 15 genealogy programs, to see how well GEDCOM interacts between them.
