SPECS must be like `MODE1 DECODER1 MODE2 DECODER2 ...'.
Each mode must be `nil', `plain', `wide', `summary' or `nov'.
If mode is `nil', corresponding decoder is set up for every modes."
SPECS must be like `MODE1 DECODER1 MODE2 DECODER2 ...'.
Each mode must be `nil', `plain', `wide', `summary' or `nov'.
If mode is `nil', corresponding decoder is set up for every modes."