Hello rickymaveety,

A base conformer is a CR2 ( Character Reference 2 ) that has all of the copyrighted morphs removed.  Material references are removed as well. 

See,  your clothing item is actually two important parts.  The OBJ file,  which is the mesh,  and the CR2 file,   which is the engine that drives the mesh.  This is the norm for all poser figures.

Now,  when you took your figure into the set up room and loaded the mouse for it's bones
( rigging ),  poser loaded both the mouses OBJ and the mouses CR2 files for you to use.  The obj is there it's just invisible.  And the CR2 is where the bones are coming from.

The mouses CR2 ,  has  many levels of embedded code with data for geometry call up,  rigging,  morphs,  and material.  Some of this data is copyrighted by the developer,  such as morphs or embedded geometry.  When you see a CR2 that has it's distribution restricted it's usually because of said morphs or embedded geometry.  ( Note because of embedded geometry universal poses and universal conformer programs and scripts,  will not work with some figures.)

Side note:    When you used posers grouping tool,  poser automatically created a new mesh for your clothing item.   You'll find it in the folder you save the clothing item to.

Now,  when you left the set up room,  the engine driving your mesh is, believe it or not,  the mouses CR2 only the OBJ ( mesh ) has changed.  Remember the two important files OBJ,  CR2.  And inside that engine ( CR2 ) is still the copyrighted data,  and if you distribute it without taking it out,  then the developer of the mouse will be asking you to please don't do that.

So this brings us back to the copyright free base conformer.  Which in essence is the mouse's CR2 file( engine ) with all the copyrighted data removed.   Making it free to distribute.

If you have any questions on how to make a base conformer feel free to ask. 

Cheers,
Patorak