"Okay, here is another question regarding creating PNGs.  If I wanted to create a PNG that only displays a message (like instructions) and does NOT link to anything, how would I go about doing that?  For instance, I'd like to post a PNG that displays ONLY a message which gives instructions so to speak like "DO THIS FIRST" or "BEFORE YOU SELECT TEXTURE....."   It should contain a "dummy" value as far as linking to a texture is concerned as I do NOT want it to link to anything.... just display a text message of sorts in a particular library (IE Materials Library or Props Library). 
I've already created the PNG file and placed my desired message on it using Photoshop, however, and I figured this wouldn't work but figured what the heck, and tried it anyway..... I placed that PNG in the desired Library folder but it does not show up. "

Directly, it can't be done. Poser only displays .png files which have the same name (except for the extension) as the files it can acutally load. In the props directory, that's .ppz or .pp2 files

So if you have a prop "MyMarvellousProp.pp2", in the props library, Poser will look for a file named "MyMarvellousProp.png" to display when showing the contents of the library (if it doesn't exist, that's when you get the "shrugging man") (OK - to be a little more pedantic, if you have a "MyMarvellousPro.rsr", it will display that, after converting it into a .png and saving that in the folder. You have to go and get rid of those pesky .rsr files yourself. But I digress..)

1 possibility occurs to me (I have a 1-track mind, so that's all you'll get).. Create a prop (from a 1-sided square), and apply the message to it as a texture. At the bottom add (in BIG LETTERS) "THIS IS JUST ADVICE. PLEASE DELETE ME NOW" (or words to that effect). Save that in the props library...(just make sure to have a copy of your advice .png ready to replace the one Poser will create).

Hope that helps,
Cheers,
Diolma