$compress(file|&bvar, blN)
$decompress(file|&bvar, blN)
Compresses the specified file or binary variable. The result is raw compressed data.
Where b indicates a binary variable in the first parameter, and lN sets a compression level of 1 to 6 (default is 6). Returns 1 for sucess, 0 for failure.
^Taken straight from the mIRC helpfile.