I posted earlier in this thread and questioned the need for all of these extra tags. There was a lot of comment.
However I agree with the last couple of poster and agree that the birth fact can be used to completely document the birth.
You can add multiple sources to a birth. For any one birth you may list the following source. Birth Certificate, census, death certificate, a family note. etc. For each birth fact there is a note where you can document the reasoning for the final data you put into the database for the fact, if there is conflicting information in the sources or there is a need for clarification.
Properly sources and noted the birth fact provides proof of parents, and data of birth.
Remember the KIS principal. If you have a unique Tag for everything you may as well put all of the sources in your database as the there will be so many tags they are useless.
Remember tags are like "keywords" You do not put every word in the story in the "Keywords" section. They are index markers to find a category of information