Can anyone explain how to make a pose file including things found in the material room?  I keep downloading great files for clothes textures which include displacement, etc.  How do they do it??!!

When you are in the Material Room, your Library tab switches to Materials. Just add your current material (or collection of materials, if you choose that option) to the Library.

You will need to ensure that you have saved any map files you are using in a safe location, since the MAT file references them wherever they are. Best to take a copy and put them in your own textures folder somewhere. It does not have to be in your Runtime, as the full path is used; but your own subfolder of the Runtime / Textures folder is probably the right place for them - this is where most commercial products will save them.

I hope this helps.

I forgot to say, the MAT file (.mt5 for a Material, .mc6 for a Material Collection) is saved in the Runtime / Libraries / Materials folder of your current Runtime.

Thank you for the reply - I wasn't very clear - looking for the ability to save the materials in a pose file, not a material file - it seems to be possible, but don't know how!

Oops, yes you did say that... my bad!
I understand that a simple change to the .mt5 / .mc6 files is all that is required, but I'll have to leave it to someone more competent to fill in the details.

Change the .mt5 or .mc6 to .pz2 and save in your pose folder.

Wheeeeeeeeeeeeeh!  Thank you both so much for the replies - at LAST I've found out how to do this - it's always simple when you know how, isn't it!! 

You have to edit the mc6 file and change mtlCollection into figure, afterwars you can save it as pz2.

ooops, you know I thought I  had forgotten something, (Not enough coffee yet!) thanks Jules!   

You're wellcome

Now I'm lost again - does this mean you have to edit the material file in a text editor?

Yes.  Just replace that one line near the top.
In MC6 the line is mtlCollection
In PZ2 the line is figure
In MT5 the line is actor $CURRENT

This is wonderful! Thank you all so much - your knowledge of Poser has saved me so much time.