This info comes directly from the readme for the v2.40b patch. I never knew these macros existed! Apparently it was left out of the original readme but added to the patch readme. The macros will also work with Breakthrough v1.0
Battlechat Macros
As an aid to players trying to coordinate team play, several macros have been built into the chat parser for Breakthrough. The following strings will be replaced with dynamic text depending on the current state of the player saying the string:
$c - The player's current condition ("almost dead", "slightly wounded")
$d - The direction the player is currently facing ("North", "South West")
$l - The location in the map where the player is ("North West corner", "East side")
$n - The teammates that are near the player ("General Wheathers and Fritz")
$w - The player's current weapon class ("rifle", "sniper")
$r - The distance from the player to whatever's in the player's sights ("85 feet")
$a - The name of the person the player currently has in his sights ("Die Commandant")
For instance, if a player said "I'm with $n at the $l" then everyone would hear "I'm with General Wheathers and Fritz at the East side." If the player said "I can see the enemy $r to the $d" then everyone would hear "I can see the enemy 100 feet to the East". These macros are mostly intended to be placed in a bound alias, so that players can coordinate movements in team on team games with a simple key press.
The distances, by default, are given in feet; but by setting g_qunits_to_feet to zero (0) the results of $r will be given in meters.
The battlechat macros can be disabled on any particular server by setting g_chat_expansion to zero (0).
Mappers who want to extend the $l macro can place info_landmark entities in their maps and make sure that the "landmark_name" attribute is set to the value they want to appear when players near the landmark use the $l macro.