Will my XCMDs/XFCNs in HyperCard work properly in SuperCard?

Like Authorware, FoxPro, Director and other programs which use XCMDs and XFCNs, SuperCard uses the XCMD interface as defined by HyperCard 1.2.x. Since the introduction of HyperCard 2.0, new HyperCard-specific callbacks have been added which, to this author's knowledge, are not supported by any other platform, including SuperCard. Externals written to the original XCMD specification should work just fine in SuperCard. Any externals using callbacks specific to HyperCard 2.x may not. If in doubt, you may need the author of the XCMD to ensure compatibility.