Hello,
Any name can be given to any file, the extensions are only useful for pre and post-processors, especially on Windows, like .slf for selafin format, which is recognised by BlueKenue, so unless it is an extension defined for Fudaa, .cli and .conlim are arbitrarily given names just to remind that it is a boundary conditions file, like "CONditions LIMites" in French. If in doubt send the files and we'll see what is inside.
With best regards,
Jean-Michel Hervouet