K-Meleon's keyboard accelerator definition file (accel.cfg) is located in the Settings Directory. It was introduced with K-Meleon 0.4 to allow customization of the accels.
Defining an accelerator is as simple as it could be:
<keys>=<command>
<keys> is a space-separated list of predefined key names.
<command> can be "ID_..." or "<pluginName>(<pluginCommand>)".
Note that plugin commands are ignored when the addressed plugin is not present i.e. not loaded.
You can define accelerators dependent on the absence/presence of a plugin:
%ifplugin <pluginName>
...
%else
...
%endif
The %else part can be omitted.
Since version 1.1, K-Meleon can have two accelerator configuration files (both named accel.cfg). The first one is located in the Default Settings Directory, the second one can be created in the User Settings Directory and is dedicated to customize the default accels. Both files use the same syntax. The user settings simply override the default settings.
See also the setaccel() macro statement.
This list is taken from K-Meleon's source code (see AccelParser.cpp).