~ default allopts structure)
%        restriction ... depending on the type, restriction to the accepted values
%        type: 'O' other, no restriction, no checking (e.g. usr_prn)
%              'S' string, no restriction
%              'I', 'R' integer or real within range restriction(1)~restriction(2)
%              'M' multiple choice - one of the elements in array restriction
%     defopts = struct(...
%       'outlev', {2, 'I', [0, Inf]}, ...
%       'outlev_file', {5, 'I', [0, Inf]}, ...
%  