NML:Testing for other NewGRFs

See the builtin functions for the functions grf_XXX. Additionally - when the presence of a NewGRF is established - their parameters can be of interest and queried. The general syntax is

identifier = param[<grfID>, <param#>]

For example

 other_newgrfs_param0 = param["NML\01", 0];
 other_newgrf_no_high_cost = param["NML\01", 1] < 5;

reads parameter 1 (the first one, counting starts at 0) from the NewGRF with the grfID "NML\01".