in the current (CVS) version of PHP3, this alias
is definend in php3/functions/sybase.c

in the current (CVS) version of PHP4, this alias
is definend in php4/ext/mssql/php_mssql.c
and implemented in php4/ext/mssql/php_mssql.c

it is documented in mssql.xml

a japanese translation is available

there is a proto in latest PHP3 source:

bool mssql_free_result(int result) Free result memory

there is a proto in latest PHP4 source:

int mssql_free_result(string result_index) Free a MS-SQL result index