Simply: Don't use advanced shaders (use the basic shader tab, that one resembles P4 a lot) and in each file, manually alter the "version 6" at the top to Version 4.01 Be sure to NOT save any characters and/or morphs with"external binary morphtargets" checked. And the stuff will be Poser 4 friendly. Of course you can't use nested folders either (runtimelibrariespropsmuralistmy furniturechairs.... Poser 4 users will only see the - to their eyes empty "muralist" folder :o)

FREEBIES! | My Gallery | My Store | My FB | Tumblr |
You just can't put the words "Poserites" and "happy" in the same sentence - didn't you know that? LaurieA
  Using Poser since 2002. Currently at Version 11.1 - Win 10.