Should one adopt the tag naming convention of an existing XML vocabulary or create one's own tag naming convention?

Hi Folks,

I am about to create an XML vocabulary.

My XML vocabulary will leverage (reuse) three existing, mature XML vocabularies.

So my XML instances will consist of tags that I created and tags from the existing, mature XML vocabularies.

For the tags that I create, what tag naming convention should I use? 

Here are two possibilities:

1. I will create a my own tag naming convention, independent of the XML vocabularies that I will use.

2. I will adopt the tag naming convention of one of the XML vocabularies that I will use. (Which one?)

What do you recommend? 

What are the tradeoffs?

/Roger