Inside Macintosh: AppleScript Scripting Additions Guide /

Chapter 3 - Writing Scripting Additions

Scripting Addition Limitations

Scripting additions are stand-alone code resources. As such they cannot have global variables. Solutions are available to circumvent this limitation in code resources. Check your compiler documentation for these solutions or see the appropriate technical notes from Apple Computer.

Scripting additions cannot use the Object Support Library (OSL). The OSL is designed to be linked into an application and initialized once. This means that a scripting addition that has to resolve object specifier records must do so internally without the use of the OSL.

Scripting additions are not chained. If two or more scripting additions in
the Scripting Additions folder have the same class and ID, only the first one found (that is, the first one in alphabetical order by name) will be installed.