If an error is detected during the Interface File compilation phase, it is reported and, in most cases, the system is set into a state which is likely to enable it to continue. No further errors will be reported until a token acceptable in the new state is found. At the end of compilation a message giving the number of errors found will be reported. For some errors, where recovery is unlikely, compilation will stop immediately.
Unless compilation is aborted, a program reading the Interface File at run time, will go on and attempt to run with the information it has found and compifl will go on to write the .ifc file which could be read by the program later. In both cases the information obtained by the program will probably be incomplete and result in some unexpected defaults being used.
ADAM Interface Module Reference Manual