XCB_DESTROY_NOTIFY & SIGTERM

 Hoping to clarify or ensure that a xcb_generic_error_t error_code of 
143 is a SIGTERM code. First time I received this and a non-xcb source 
claims this is so.
 I got the error on a 2 window 'app' after the XCB_DESTROY_NOTIFY of 
the first window. It appears only after what I'm guessing was a 
'complete' clean up of first window's resources. By this I mean the 
'last reference' to a cairo_surface_t is destroyed. I can comment out 
the 'finish/destroy' code to not receive code 143. I also assume I 
would get this code on a single window 'app', but don't see because on 
XCB_DESTROY_NOTIFY I exit the event loop and disconnect.
 If the non-xcb source is to be believed, the 143 SIGTERM is stating 
the X-server correctly terminated the 'process' of the first window, 
and only resources for the second window remain.
 Is this a correct interpretation of signals?
Steve