FlashDevelop processes strings in some cases for system, plugin and user defined arguments. This functionality provides dynamic content to be used in resolving paths and custom strings. Currently arguments are processed in the snippets and the menu item's tag attribute (MainMenu.xml).

FD defines following arguments:

@APPDIR - Directory where FlashDevelop is installed
@SELTEXT - Currently selected text in FlashDevelop editor window
@QUOTE - Quote (") to be used in places that dont allow normal quote usage
@CLIPBOARD - Clipboard text
@CURFILENAME - Name of the currently edited file
@CURFILE - Full path with file name of the currently edited file
@CURDIR - Path of the currently edited file
@TIMESTAMP - System specified timestamp
@CURWORD - Current word specified by caret position
@SELFILE - User selected file (with openFileDialog)
@TRGFILE - User selected file (with saveFileDialog)
@SELDIR - User selected directory (with browseFolderDialog)
@DESKTOP - System specified desktop directory
@SYSTEM - System specified system directory
@PROGDIR - System specified programs directory
@PERSONAL - System specified personal files directory
@WORKINGDIR - Current working directory

After these arguments have been processed, the processor will look for user defined arguments (defined in Settings.xml):
FlashDevelop.UserDefined.@SAMPLEARG

After the user defined arguments have been processed FD sends a notify to all plugins to process the text.

ASCompletion defines other contextual arguments:

See Actionscript Context Help

ProjectExplorer defines other contextual arguments:

Any macro from the project properties' "Build Event" builder dialog can be used here as well. Just make the var uppercase, for instance:

$(ProjectName) becomes @PROJECTNAME