Map it to info tool - usually key a.
Not sure if you are meaning map the screen recorder to the letter 'a' (which would cause issues when typing), or Map the info tool to the key allocated for the screen recorder (i.e. F11/F12), in which case can multiple keys be mapped to a single command?
Also, how are the 'Fx (F2,F3...F12) keys listed in menuconf.tab? (I see home HOME and END listed, so I am guessing it is just F12 as an example, but I can't actually find any reference to an 'Fx' Key).
Another one I would like to map is <Alt>+<F4> to exit (Simutrans is about the only application I have found on Windows that does not recognize this command as exit). I realize there is ^ to indicate the use of <Ctrl>, but not sure if there is a similar convention for <Alt>.
(and also switching to the info tool isn't quite 'do nothing' but I guess it is close, and the best option currently available with Simutrans).
Also, in regards to the original comments, I think having the option of a keysconf.tab in the user directory that overrides menuconf.tab would be good, as I would like to be able to set keys for all PakSets I play, without having to go in and manually edit each PakSet's menuconf.tab file (also when a new version of the PakSet is released, if I just download and extract it over top, it overwrites the menuconf.tab).