termcap and TERM detection

[E. Eusey]

The secondary screen functionality on my xterm (rxvt-unicode) was acting 
strangly.  So, following the advice at:

http://cvs.schmorp.de/browse/*checkout*/rxvt-unicode/doc/rxvt.7.html

I added an rxvt-unicode termcap entry to my termcap file and ran 
cap_mkdb.  After login, I'm able to 'setenv TERM rxvt-unicode' and 
everything works perfectly.

However, when running urxvt initially, it detects the $TERM as 'rxvt', 
not 'rxvt-unicode'.  How is the $TERM variable determined by the system? 
  Is there a way to detect my new termcap entry?  Any help would be 
greatly appreciated.

Evan