Dreamweaver may not search your custom extensions (.inc, .lib) files if the extensions are not added to the Extensions.txt file. If you are reading this, you will need to add your custom extensions to the Extension.txt file.
Here is how to Locate this file:
“To add file types to the Extensions.txt file: Locate the Extensions.txt file within the Dreamweaver user configuration folder. The location of this folder depends on the operating system and the version of Dreamweaver:
- Dreamweaver CS3 on Windows Vista: C:\Users\[username]\AppData\Roaming\Adobe\Dreamweaver 9\Configuration
- Dreamweaver 8 on Windows Vista: C:\Users\[username]\AppData\Roaming\Macromedia\Dreamweaver 8\Configuration
- Dreamweaver CS3 on Windows XP: C:\Documents and Settings\[username]\Application Data\Adobe\Dreamweaver 9\Configuration
- Dreamweaver 8 on Windows XP & 2000: C:\Documents and Settings\[username]\Application Data\Macromedia\Dreamweaver 8\Configuration
- Dreamweaver CS3 on Mac OS X: Mac HD:Users:[username]:Library:Application Support:Adobe:Dreamweaver 9:Configuration
- Dreamweaver 8 on Mac OS X: Mac HD:Users:[username]:Library:Application Support:Macromedia:Dreamweaver 8:Configuration "
Directly taken from this Page: http://kb2.adobe.com/cps/164/tn_16410.html
For Example, i just added the .lib extension to my Extensions.txt File (LIB Upper Case)