need to have '.ad' suffix.
Note that, the distdef format used in these files must be the non-source
-format.
+format, even if the file is source file. This is because the distdefs
+are processed during source tree preparation, and the source file will
+have all distdefs removed when it is compiled.
@menu
* Distdefines:: Using distdefs in files
.hh
@end example
+Also, any file that has '.in' suffix with any of the above source file
+suffixes, the format inside the file must follow the source code format.
Using distdefs in any other file must follow the non-source format.
+Example:
+@example
+ .c.in
+ .h.in
+@end example
+
+In this example, in both of the files the source code format is used.
+
@node Invoking Autodist
@chapter Invoking Autodist