Hi Domot,
I think it‘s more or less straightforward. I‘d suggest the following procedure:
1. Decide which phone should have all cards from both phones merged together
2. Back up your flashcards database from that phone (just to be safe)
3. Make sure you have the same (or more) dictionaries installed on the destination phone as on the source phone
4. Export all flashcards from the source phone to XML with the following settings:
5. Send the exported XML file to the destination phone
6. a) Import the XML file on the destination phone with the following settings (if you wish the definitions from the source phone to carry over onto the destination phone):
6. b) If you wish the definitions on the destination phone to remain as they were, you could use these settings:
To ascertain that the settings are right for you, you could also check Pleco's manual which has explanations for each of them.
I hope that definitions from non-exportable dictionaries will be assigned to those dictionaries again when you import them from an XML that doesn't contain the definitions. You'd have to try. You can always go back by restoring your flashcards backup.
Hope this helps,
Shun