The last line of a text stream does not require a terminating newline character.

Space characters written out to a text stream immediately before a newline character do appear when read back in.

No NUL characters are appended to a binary output stream.

The file position indicator of an append mode stream is initially placed at the end of the file.

A write to a text stream causes the associated file to be truncated beyond the point where the write occurred if this is the behavior of the device category of the file.

If semihosting is used, the maximum number of open files is limited by the available target memory.

A zero-length file exists, that is, where no characters have been written by an output stream.

A file can be opened many times for reading, but only once for writing or updating. A file cannot simultaneously be open for reading on one stream, and open for writing or updating on another.

Local time zones and Daylight Saving Time are not implemented. The values returned indicate that the information is not available. For example, the gmtime() function always returns NULL.

The status returned by exit() is the same value that was passed to it. For definitions of EXIT_SUCCESS and EXIT_FAILURE, see the header file stdlib.h. Semihosting, however, does not pass the status back to the execution environment.

The error messages returned by the strerror() function are identical to those given by the perror() function.

If the size of area requested is zero, calloc() and realloc() return NULL.

If the size of area requested is zero, malloc() returns a pointer to a zero-size block.

abort() closes all open files and deletes all temporary files.

fprintf() prints %p arguments in lowercase hexadecimal format as if a precision of 8 had been specified. If the variant form (%#p) is used, the number is preceded by the character @.

fscanf() treats %p arguments exactly the same as %x arguments.

fscanf() always treats the character "-" in a %...[...] argument as a literal character.

ftell(), fsetpos() and fgetpos() set errno to the value of EDOM on failure.

perror() generates the messages shown in Table 12.

the validity of a filename

whether remove() can remove an open file

the effect of calling the rename() function when the new name already exists

the effect of calling getenv() (the default is to return NULL, no value available)

the effect of calling system()

the value returned by clock().