Compatible RAs
Jetboy - your manual is being economical with the truth!
TCAS equipments communicate with each other when determining what RAs to post to their flight crews. When it is agreed that one TCAS will post 'Descend', for example, the other will post a manoeuvre that does not conflict: this will not necessarily be a 'Maintain Rate' style of advisory unless this is appropriate. In such circumstances, a 'Climb' advisory would double the difference in altitude between both aeroplanes at the Closest Point of Approach.
For more information see, the 'Tcas' thread in this Forum, and read also the excellent briefings given by Cpt PitBull both in the ATC Forum, 'Nasty Incident' and in the Reporting Points Forum, 'Accident in Southern Germany'.