No_Map is used to indicate no image file for a parameter which normally has an image.

Sometimes people put it in quotes "No_Map" which makes Poser look for it.  If a particular figure, prop or mat pose (mc6 or mt5 as well) looks for a file , open it in a text editor and check for the text in quotes. 

heres part of a mat pose to show what it should look like

 

        bumpStrength 1
        ksIgnoreTexture 0
        reflectThruLights 1
        reflectThruKd 0
        textureMap ":Runtime:Textures:PW Texture files:Scrubs:ScrubsTop-Surgical.jpg"
                 0 0
        bumpMap NO_MAP
        reflectionMap NO_MAP
        transparencyMap NO_MAP
        ReflectionColor 1 1 1 1
        reflectionStrength 1