Yes, I think that including the datum is the way to do, and the datum to be included should be mapped according to the tectonic plate being mapped. The program

Yes, I think that including the datum is the way to do, and the datum to be included should be mapped according to the tectonic plate being mapped. The program can then include the table of conversions between them, in order to plot the data on the map correctly (e.g. in case it includes multiple tectonic plates, or to convert between GPS and map coordinates, etc; this conversion might require also knowing the correct time). If you are plotting on a map then you can either use the same datum if it is known to be the same one for the entire map (e.g. because it is a single tectonic plate being mapped and using that plate's datum), or you can convert to the proper datum if necessary. When you are mapping only one tectonic plate then you will not have to worry about the conversion because it will use that plate's datum and then it will already be correct. This is true with text as well; the character encoding can be stored with it. You can then select a suitable font if you have it, or otherwise use conversion for fallback if necessary. (In some cases, e.g. between UTF-8 and UTF-16 and UTF-32, this can be done losslessly, because they are all encodings of the same character set (this can also work if converting to a superset, e.g. ASCII to Unicode or JIS to TRON). Other times, that isn't ideal and doesn't work very well; like the example given above about maps with multiple tectonic plates, you can have text with multiple languages, too. And, again, the conversion can involve other stuff too (time in the case of WGS84, but in the case of character encodings (especially Unicode) it is much more complicated).) And then, another comment mentions "3PM (time zone)". Even in that case, converting time zones will require knowing the date as well (and in some cases it might be ambiguous); "3PM" is not good enough. In all of these cases, improved documentation is helpful because it can sometimes avoid these kind of problems. If the documentation makes it clear what map coordinates to use and what character encodings to use, then it can be helpful.