The ProTeX system is currently a development aid and is not necessarily yet complete. It is imaginable that the documenting conventions described in the appendix A.1 will be extended to include new markers and keywords.
The automatic generation of Fortran90 interface blocks is another possible extension. Although the interface blocks are compilable code, they are in a sense also documentation as they indicate to users how routines are properly called.
Whereas the interface blocks should be frozen for a production release they do change often during the development cycle, as the routines are revised. This engenders a consistency problem, since not only the subroutine declarations need to be changed but also the corresponding interface blocks. For this reason, among others, developers often do not write any interface blocks at all, much to the detriment of the final code. In the future we could foresee the automatic generation of interface blocks from the given code as an aid to the developer's only. When the code is fixed for production release the interface blocks may not be regenerated, since the interfaces have been frozen.