QuakeForge allows the structure of the game data directory tree to be specified at run time.

The default configuration is given below, but can be overridden by setting the fs_dirconf Cvar to point to a configuration file (eg, "~/.quakeforge/gamedir.conf")

QF = {
    Path = "QF";
};
Quake = {
    Inherit = QF;
    Path = "id1";
    GameCode = "progs.dat";
    HudType = "id";
};
QuakeWorld = {
    Inherit = (Quake);
    Path = "qw";
    SkinPath = "${path}/skins";
    GameCode = "qwprogs.dat";
    HudType = "id";
};
"Hipnotic" = {
    Inherit = (Quake);
    Path = "hipnotic";
    HudType = "hipnotic";
};
"Rogue" = {
    Inherit = (Quake);
    Path = "rogue";
    HudType = "rogue";
};
"qw:qw" = {
    Inherit = (QuakeWorld);
};
"qw:*" = {
    Inherit = (QuakeWorld);
    Path = "$gamedir";
};
"nq:*" = {
    Inherit = (Quake);
    Path = "$gamedir";
};
"hipnotic:*" = {
    Inherit = (Hipnotic);
    Path = "$gamedir";
};
"rogue:*" = {
    Inherit = (Rogue);
    Path = "$gamedir";
};
"abyss" = {
    Inherit = (Quake);
    Path = "abyss";
};
"abyss:*" = {
    Inherit = (abyss);
    Path = "$gamedir";
};

The directory config is a collection of tags with collections of attributes. Normally, the tags will be in the form of either "[name]" or "[name]:*". The first form is usually used for allowing inheritance (via the Inherit attribute)

Supported attributes are:

Path: The relative path of the mod directory.
GameCode: The name of the mod progs file. This is relative to the mod directory
HudType: The name of the hud style. Currently, "id", "hipnotic" and "rogue" are supported. Has no effect in quakeworld.
SkinPath: Directory to which downloaded skins will be saved. This is relative to the QuakeForge data directory, and thus the default configuration uses ${path}. This attribute is ignored by nq clients and servers.
SoundPath: Where to look for sounds. Defaults to ${path}/sound
ModelPath: Where to look for models. Defaults to ${path}/progs
MapPath: Where to look for maps. Defaults to ${path}/maps.
ShotsPath: Where to write screenshots. Defaults to QF.

Attribute allow variable substitution. Variables can take the form of either $NAME or ${NAME}, where the latter is useful when the end of NAME is ambiguous (eg, ${NAME}STUFF vs $NAME/STUFF).

Supported vars are:

gamedir: This is the current mod directory as specified by either -game [modname] on the command line (nq) or the gamedir [modname] console command.
path: This is the first directory in the Path attribute. If the current tag does not set the Path attribute, this variable will be undefined.
$: The way to get $ into an attribute is by using $$