WordPress POST tags

Trying to use the new RSS import tool to import several posts…

These tags are working fine

<ITEM>
<PubDate></PubDate>
<Title></Title>
<Description></Description>
<Category></Category>
</ITEM>

BUT I cannot figure out how to get TAGS or EXCERPT or FEATURED IMAGE set and I cannot (for the life of me) find where these tags are listed in the WP Codex.

Can anyone clue me in as to what these tags are and/or where to find a listing of them???

Thanks!