Not that I know of... Sounds like you'd want to use SIDECHAT.
unitname SideChat "Everyone take the flag!"
unitname being the unit/player speaking. It only shows up to players on the same side, but it's just text in upper/left, not the larger text that fades in and out like titletext.
'corse my experience is somewhat limited -- maybe someone else knows of a better way. Not sure if "hint" can be specific to players or side.
?