The available placeholders are:
%D .. Replace with $(CONFIG_VERSION_DIST), default to "OpenWrt"
%d .. Like %D, but all characters made lowercase and spaces substituted with "_" (e.g. "openwrt")
%N .. Replace with $(CONFIG_VERSION_NICK), default to the build tree release (e.g. "Attitude Adjustment")
%n .. Like %N, but all characters made lowercase and spaces substituted with "_" (e.g. "attitude_adjustment")
%V .. Replace with $(CONFIG_VERSION_NUMBER), default to the build tree release (e.g. "r31262")
%v .. Like %V, but all characters made lowercase and spaces substituted with "_"
%C .. Replace with $(CONFIG_VERSION_NUMBER), default to "Bleeding Edge"
%c .. Like %C, but all characters made lowercase and spaces substituted with "_" (e.g. "bleeding_edge")
%U .. Replace with $(CONFIG_VERSION_REPO), default to "http://downloads.openwrt.org/snapshots/trunk/%T/packages"
%R .. Replace with the current build tree revision (e.g. "r31262" or "75488c4a05b8033cf69e91874a61852db7ba9c6c")
%T .. Replace with the current target (e.g. "ar71xx")
%S .. Replace with the current target/subtarget combo (e.g. "adm5120/router_le")
SVN-Revision: 31262
Jo-Philipp Wich