img: http://tinypic.com/r/34raqvm/5
I received a Flash project from an outside source. In it I found that some library items had these grey, dashed guide lines. It seems like they are used for assigning resize boundaries or something. Anyways, I can't reproduce them in my own library elements nor can I find any information on them. What terms should I use to google so I can read up on these?
Exactly. It's called 9-slice scaling.
http://www.sephiroth.it/tutorials/flashPHP/scale9/
http://www.adobe.com/devnet/flash/articles/concept_9-slice.html