costmap plugin question

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Does placing plugin definitions under the namespace restrict them to those functions. Even if the parameters are specified in another file but under the same namespaces. If I use the definitions below it does not complain but ignores the parameters under the plugin namespaces, if I remove the plugin definitions and comment out the plugin name spaces then it sees the parameters.

global_costmap:
       plugins:
        - {name: footprint_layer, type: "costmap_2d::FootprintLayer"}
        - {name: static_map_layer, type: "costmap_2d::StaticLayer"}
        - {name: obstacle_layer,  type: "costmap_2d::VoxelLayer"}
        - {name: inflation_layer,   type: "costmap_2d::InflationLayer"}   
      footprint_layer:
          footprint:  []
      obstacle_layer:
               :
               :

local_costmap:
       plugins:
        - {name: footprint_layer, type: "costmap_2d::FootprintLayer"}
        - {name: obstacle_layer,  type: "costmap_2d::VoxelLayer"}
        - {name: inflation_layer,   type: "costmap_2d::InflationLayer"}
      footprint_layer:
          footprint:  []
               :
               :